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TABLE OF CONTENTS

As Filed with the Securities and Exchange Commission on July 23, 2004May 19, 2005

Registration No. 333-114639333-124234



SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549


Amendment No. 21
to
Form S-3S-3/A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933


Intrusion Inc.

(Name of Issuer in Its Charter)

DELAWARE357675-1911917

(State or other jurisdiction of
incorporation or organization)
3576
(Primary Standard Industrial
Classification Code Number)
75-1911917
(I.R.S. Employer
Identification Number)

MICHAEL PAXTON
Vice President and Chief Financial Officer
Intrusion Inc.
1101 E. Arapaho Road
Richardson, Texas 75081
Telephone: (972) 234-6400
Facsimile: (972) 301-3892
Address and telephone number of principal executive offices,
principal place of business and agent for service


copies to:

THOMAS R. NELSON
AKASH D. SETHI
Patton Boggs LLP
2001 Ross Avenue, Suite 3000
Dallas, Texas 75201
Telephone: (214) 758-1500
Facsimile: (214) 758-1550

        Approximate Date of Commencement of Proposed Sale to the Public:    As soon as practicable after the Registration Statement becomes effective.

        If the only securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. o

        If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box: ý

        If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

        If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. o

        If delivery of the Registration Statement is expected to be made pursuant to Rule 434, check the following box. o


        The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the registration statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.




The information in this preliminary prospectus is not complete and may be changed. These securities may not be sold until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted

SUBJECT TO COMPLETION, DATED JULY 23, 2004MAY 19, 2005

PRELIMINARY PROSPECTUS

2,673,6971,658,190 SHARES

Intrusion Inc.
Common Stock


        This prospectus relates to up to 2,673,6971,658,190 shares of our common stock that the selling stockholders named on page 2116 in this prospectus, or their respective pledgees, donees, transferees or other successors in interest that receive these shares as a gift, partnership distribution or other non sale related transfer, may offer for resale from time to time.

        Of the 2,673,6971,658,190 shares of common stock to which this prospectus relates:

        The prices at which these stockholders may sell the shares will be determined by the prevailing market prices for the shares or in negotiated transactions. We will not receive any of the proceeds from the sale of the shares, but we will receive the exercise price of the warrants if they are exercised for cash. If all of the warrants for which we are registering the underlying shares of our common stock are exercised for cash, as of the date of this prospectus, we would receive an aggregate of approximately $1,952,512.03.$1,642,582.30

        Our common stock is currently quoted on The Nasdaq SmallCap Market under the symbol "INTZ." On July 22, 2004,May 13, 2005, the closing price for our common stock as reported by The Nasdaq SmallCap Market was $1.10. All share numbers and related price information contained in this prospectus reflect the effect of a four-for-one (4:1) reverse stock split of our common stock on March 29, 2004.$2.26.

An investment in our common stock involves substantial risk. These risks are described under the caption "Risk Factors" beginning on page 43 and the section entitled "Additional Factors That May Affect Future Results of Operations" in the documents we file with the Securities and Exchange Commission that are incorporated by reference in this prospectus.


Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is                        , 2004.2005.



TABLE OF CONTENTS

INTRUSION INC.2
RISK FACTORS4
INTRUSION INC.

RISK FACTORS

NOTE REGARDING FORWARD-LOOKING STATEMENTS
13

DESCRIPTION OF SECURITIES AND RELATED TRANSACTIONS
14

PLAN OF DISTRIBUTION
18

USE OF PROCEEDS
20

SELLING STOCKHOLDERS
20

LEGAL MATTERS
23

EXPERTS
23

WHERE YOU CAN FIND ADDITIONAL INFORMATION
23


INTRUSION INC.

General

        We develop, market and support a family of network intrusion prevention, intrusion detection, regulated information compliance and detection systemsdata privacy protection products. Our product families include the Compliance Commander™ for regulated information and data privacy protection, Intrusion SpySnare™ for real-time inline blocking of spyware and unwanted peer-to-peer (P2P) applications, and Intrusion SecureNet™ for network intrusion prevention and detection. Intrusion's products help protect critical information assets by quickly detecting, protecting, analyzing and reporting attacks or misuse of classified, private and regulated information compliance systems that address vital security issues facing organizations with mission critical business applications or housing classified, confidential, or customer information assets. We currently provide network securityfor government and regulated information compliance solutions under our SecureNet family of hardware and software solutions.enterprise networks.

        We market and distribute our products through a direct sales force to end-users, distributors and by numerous domestic and international system integrators, managed service providers and value-added resellers. Our end-user customers include high technology, e-commerce, manufacturing, government entities, military, financial institutions, telecommunications, retail, transportation, health care,healthcare, insurance, entertainment, utilities and energy companies, government agencies, financial institutions, and academic institutions. Essentially, our end-user can be defined as "any end-user requiring network security solutions for protecting their mission critical data."

        We were organized in Texas in September 1983 and reincorporated in Delaware in October 1995. For more than 15 years, we provided local area networking equipment and were known as Optical Data Systems or ODS Networks. On April 17, 2000, we announced plans to sell, or otherwise dispose of, our networking divisions, which included our Essential Communications division and our local area networking assets. In accordance with these plans, we have accounted for these businesses as discontinued operations. On June 1, 2000, we changed our name from ODS Networks, Inc. to Intrusion.com, Inc., and our NASDAQ ticker symbol from ODSI to INTZ to reflect our focus on intrusion detection solutions. On November 1, 2001, we changed our name from Intrusion.com, Inc. to Intrusion Inc.

        Our principal executive offices are located at 1101 East Arapaho Road, Richardson, Texas 75081, and our telephone number is (972) 234-6400. Our website URL iswww.intrusion.com. Information contained in or linked to our website are not a part of this prospectus. References to "we," "us" and "our" in this prospectus refer to Intrusion Inc. and its subsidiaries.



This Prospectus

        This prospectus relates to up to 2,673,6971,658,190 shares of our common stock that the selling stockholders listed on page 21,16, or their respective pledgees, donees, transferees or other successors in interest that receive these shares as a gift, partnership distribution or other non-sale related transfer, may offer for resale from time to time. These shares include shares of our common stock that are currently outstanding andrepresent shares of our common stock underlying shares of our convertible preferred stock and warrants that were issued to the selling stockholders in various transactions. These transactions are summarized below and are more fully described under the section entitled "Description of Securities and Related Transactions" beginning on page 146 of this prospectus.

The Transactions

Private Placement

        On March 25, 2004,28, 2005, we entered into a Securities Purchase Agreement with various investors, including G. Ward Paxton, our Chairman, President and Chief Executive Officer, and James F. Gero, a member of our Board of Directors, pursuant to which the investors purchased 1,000,0001,065,200 shares of our Series 2 5% convertible preferred stock and warrants to purchase up to 556,619532,600 shares of our common stock. Mr. Paxton and Mr. Gero invested an aggregate of $550,000 in the private placement in exchange for 220,000 shares of the preferred stock and warrants to purchase an aggregate of 110,000 shares of our common stock.



        Our agreement with these investors requires us to register an aggregate of 2,146,950all 1,597,800 shares of our common stock underlying thethese shares of preferred stock and the warrants. These shares cover the number of shares of our common stock issuable by us upon conversion of the preferred stock and upon the exercise of the warrants. This prospectus includes all of these shares as well as 462,338warrants, including the 330,000 shares of outstanding common stock we agreed to include on behalf of current stockholders.underlying the preferred stock and warrants acquired by Mr. Paxton and Mr. Gero.

Compensation of Placement Agent

        Black Point Partners,Stonegate Securities, Inc. acted as our placement agent in connection with both the private placement. As part of its compensation, we issued Black Point Partners a warrantwarrants to purchase an aggregate of the 64,40960,390 shares of our common stock.stock to two affiliates of Stonegate. On May 17, 2005, these affiliates transferred their warrants and the underlying shares to Crestview Capital Master LLC. This prospectus includes all of these shares.




RISK FACTORS

        You should carefully consider the risks below and those contained in the section entitled "Factors That May Affect Future Results of Operations" in the documents we file with the SEC that are incorporated by reference in this prospectus, specifically the factors included in our Form 10-K10-KSB for the year ended December 31, 2003,2004, and our Quarterly Report on Form 10-Q10-QSB for the quarter ended March 31, 2004,2005, before making an investment decision. The risks described below and incorporated herein are those we currently believe may materially affect us.

If we fail to respond to rapid technological changes in the network security industry, we may lose customers or our products may become obsolete.

        The network security industry is characterized by frequent product introductions, rapidly changing technology and continued evolution of new industry standards. We must also introduce upgrades to our products rapidly in response to customer needs such as new computer viruses or other novel external attacks on computer networks. In addition, the nature of the network security industry requires our products to be compatible and interoperable with numerous security products, networking products, workstation and personal computer architectures and computer and network operating systems offered by various vendors, including our competitors. As a result, our success depends upon our ability to develop and introduce in a timely manner new products and enhancements to our existing products that meet changing customer requirements and evolving industry standards. The development of technologically advanced network security products is a complex and uncertain process requiring high levels of innovation, rapid response and accurate anticipation of technological and market trends. We cannot assure you that we will be able to identify, develop, manufacture, market or support new or enhanced products successfully in a timely manner. Further, we or our competitors may introduce new products or product enhancements that shorten the life cycle of our existing products or cause our existing products to become obsolete.

Our revenues have declined from $16.7 million in 2001 to $6.5 million in 2003 in connection with a shift to sales of our newer product lines. If our network intrusion detection and regulated information compliance system products do not achieve market acceptance, our revenues will suffer.

        Over the past three years, we have transitioned our sales strategy from our lower margin SecureCom and PDS security appliance products to the development and sales of our higher margin SecureNet network intrusion detection products. During this transition, sales of our new products were not enough to counteract the loss in sales associated with our older products. As a result, our net revenues have declined from approximately $16.7 million in 2001, to approximately $7.8 million in 2002 and approximately $6.5 million in 2003. In addition, our revenues for the first quarter of 2004 are $1.3 million as compared to $1.5 million for the same period in 2003.

        Our new network security products and regulated information compliance systems have only been in the market place for a limited period of time and may have longer sales cycles than our previous products. Although response to our products has been positive, we have not yet received broad market acceptance. We cannot assure you that our present or future products will achieve market acceptance on a sustained basis.

        In order to achieve market acceptance and achieve future revenue growth, we must introduce complementary security products, incorporate new technologies into our existing product lines and design, develop and successfully commercialize higher performance products in a timely manner. We cannot assure you that we will be able to offer new or complementary products that gain market acceptance quickly enough to avoid decreased revenues during current or future product introductions or transitions.



We resemble a developmental stage company and our business strategy may not be successful.

        From our founding in 1983 until 2000, we derived substantially all of our revenue from the design, manufacture and sale of local area networking equipment. In order to permit us to focus our resources solely on developing and marketing our network security products, on April 17, 2000, we announced our plans to sell our local area networking assets and related networking divisions.

        As a result of these sales, we now depend exclusively on revenues generated from the sale of our networks security products which have received limited market acceptance. Moreover, we have only recently introduced our regulated information compliance systems, and the market for these products has only begun to emerge. Consequently, we resemble a developmental stage company and will face the following inherent risks and uncertainties:

        Our business strategy may not successfully address these risks. If we fail to recognize significant revenues from the sales of our network security products and regulated information compliance systems, our business, financial condition and operating results would be materially adversely affected.

We had a net loss of $1.3 million and an accumulated deficit of $45.5 million as of the quarter ending March 31, 2004. As a result, we must generate substantially greater revenues from sales in order to achieve profitability.

        We have incurred significant operating losses and are uncertain about our future operating results. For the quarter ended March 31, 2004, we incurred a net loss of $1.3 million and had an accumulated deficit of approximately $45.5 million at March 31, 2004. In addition, our revenues have declined from $16.7 million in 2001, to $7.8 million in 2002, and $6.5 million in 2003. We need to generate and sustain substantially greater revenues from the sales of our products if we are to achieve profitability. If we are unable to achieve these greater revenues, our losses will continue indefinitely, and we may never achieve or sustain profitability or generate positive cash flow.

We face intense competition from both start-up and established companies that may have significant advantages over us and our products.

        The market for network security solutions is intensely competitive. There are numerous companies competing with us in various segments of the data security markets, and their products may have advantages over our products in areas such as conformity to existing and emerging industry standards, interoperability with networking and other security products, management and security capabilities, performance, price, ease of use, scalability, reliability, flexibility, product features and technical support.



        Our principle competitors in the network intrusion and detection market include Internet Security Systems, Inc., Cisco Systems, Inc., Symantec, Inc., Netscreen Technologies, Inc., Tipping Point Technologies Inc. and NFR Security, Inc. The market for regulated information compliance systems is relatively new. Our competitors in this market include a number of start up companies that have entered the market in the last two years. However, as this market develops, we expect increased competition from both start up and established companies. Our current and potential competitors may have one or more of the following significant advantages over us:

        Although we believe that our focus on network perimeters with market leading VPN/firewall control technology and network intrusion detection visibility technology that reduce the total cost of ownership provides us with an advantage with large organizations with complex security requirements, we cannot assure you that our products will achieve market acceptance or that we will be able to compete successfully with our existing or new competitors.

Military actions may disrupt our business by reducing spending our products, increasing our costs and affecting our international operations.

        United States military actions or other events occurring in response to or in connection with them, including future terrorist attacks, actual conflicts involving the United States or its allies or military or trade disruptions could impact our operations by:


        Should these events occur, our business, operating results and financial condition could be materially and adversely affected.

Our products can have long sales and implementation cycles which may result in us incurring substantial expenses before realizing any associated revenues.

        The sale and implementation of our products to large companies and government agencies typically involves a lengthy education process and a significant technical evaluation and commitment of capital and other resources. This process is also subject to the risk of delays associated with customers' internal budgeting and other procedures for approving capital expenditures, deploying new technologies within their networks and testing and accepting new technologies that affect key operations. As a result, sales and implementation cycles for our products can be lengthy, and we may expend significant time and resources before we receive any revenues from a customer or potential customer. Our quarterly and annual operating results could be materially harmed if orders forecasted for a specific customer for a particular period are not realized.



Our cash, cash equivalents, and investments declined from $10.7 million to $2.7 million during 2003. As a result of our expected continuing net cash outflows, we may not have sufficient cash to operate our business.

        As of December 31, 2003, we had cash, cash equivalents and investments in the amount of approximately $2.7 million, down from approximately $10.7 million as of December 31, 2002. Although we believe the additional $5.0 million in gross proceeds we received in connection with a private placement of preferred stock and warrants we completed on March 25, 2004 will provide us with sufficient cash resources to finance our operations for the next twelve months, the sufficiency of our cash resources may depend to a certain extent on general economic, financial, competitive or other factors beyond our control. Moreover, despite our actions to reduce costs and improve profitability, we expect our net operating losses and net operating cash outflows to continue through at least the first half of 2004. We do not currently have any further arrangements for financing, and we may not be able to secure additional debt or equity financing on terms that are acceptable to us, or at all, at the time when we need this financing. If our business does not generate sufficient cash flow from operations and sufficient financing resources are not available, we may not be able to operate or grow our business, pay our expenses when due or fund our other liquidity needs.

Our failure to realize the expected benefits of our recent restructuring efforts could adversely affect our operating results.

        During the first quarter of 2004, we continued a restructuring plan and cost reduction efforts which resulted in $0.1 million in severance costs. Since we began restructuring in 2002, we have incurred approximately $0.8 million in restructuring charges, severance, and related expenses. The objective of our restructuring plan was to reduce our cost structure to a sustainable level that is consistent with our current cash resources and the general economic climate. We have also implemented other strategic initiatives to strengthen our operations, such as reductions in our work force and facilities and aligning our organization around our business objectives. Any further work force reductions could result in temporary reduced productivity of our remaining employees. Additionally, our customers and prospects may delay or forgo purchasing our products due to a perceived uncertainty caused by our restructuring and other changes. Failure to achieve the desired results of our initiatives could seriously harm our business, results of operations and financial condition.

Consolidation in the network security industry may limit market acceptance of our products.

        Several of our competitors have acquired security companies with complementary technologies in the past, and we expect consolidation in the network security industry to continue in the future. These acquisitions may permit our competitors to accelerate the development and commercialization of broader product lines and more comprehensive solutions than we currently offer. Acquisitions of vendors or other companies with which we have a strategic relationship by our competitors may limit our access to commercially significant technologies. Further, business combinations in the network security industry are creating companies with larger market share, customer bases, sales forces, product offerings and technology and marketing expertise which may make it more difficult for us to compete.



Sales to government agencies accounted for 34.5% of our revenues the quarter ended March 31, 2004 and 17% of our revenues for the year ended December 31, 2003. Sales to government customers involve unique risks which could adversely impact our revenues.

        We derived 34.5% of our revenues from sales to various U.S. government entities for the quarter ended March 31, 2004, and 17.0% of our revenues from these sales for the year ended December 31, 2003. We expect to continue to derive a substantial portion of our revenues from U.S. government customers in the future. Sales to the government present risks in addition to those involved in sales to commercial customers, including potential disruption due to appropriation and spending patterns and he government's right to cancel contracts and purchase orders for its convenience. General political and economic conditions, which we cannot accurately predict, directly and indirectly may affect the quantity and allocation of expenditures by federal departments. In addition, obtaining government contracts may involve long purchase and payment cycles, competitive bidding, qualification requirements, delays or changes in funding, budgetary constraints, political agendas, extensive specification development and price negotiations and milestone requirements. Each government entity also maintains its own rules and regulations with which we must comply and which can vary significantly among departments. As a result, cutbacks or re-allocations in the federal budget or losses of government sales due to other factors could have a material adverse effect on our revenues and operating results.

We derived 32.5% of our revenues from international sales in the quarter ended March 31, 2004, and 31.4% of our revenues from these sales for the year ended December 31, 2003. Our ability to sell our products internationally are subject to certain risks which could harm our business.

        Sales to foreign customers accounted for approximately 31.4% of our revenues for the year ended December 31, 2003, and 32.5% of our revenues for the quarter ended March 31, 2004. We expect sales to foreign customers to continue to represent a significant portion of our revenues in the future. Our international operations are subject to many inherent risks that may adversely affect our business, financial condition and operating results, including:


Sales through indirect channels accounted for 38% of our revenues for the quarter ended March 31, 2004 and 57% of our revenue for the year ended December 31, 2003. Our revenues will suffer if we do not expand our sales through, or receive the anticipated benefits from our sales through, indirect sales channels.

        We derived 38% of our revenues for the quarter ended March 31, 2004, and 57% of our revenue for the year ended December 31, 2003 from sales through indirect sales channels, such as distributors, value added resellers, system integrators, original equipment manufacturers and managed service providers. We believe we must expand our sales through these indirect channels in order to increase our revenues. Although we are actively pursuing a strategy to increase the percentage of our revenues generated through these indirect sales channels, we cannot assure you that our products will gain market acceptance in these indirect sales channels or that sales through these indirect sales channels will increase our revenues as expected. Further, many of our competitors are also trying to sell their products through these indirect sales channels which could result in lower prices and reduced profit margins for sales of our products.

We must adequately protect our intellectual property in order to prevent loss of valuable proprietary information.

        We rely on a combination of patent, copyright, trademark and trade secret laws, confidentiality procedures and non-disclosure agreements to protect our proprietary technology. However, unauthorized parties may attempt to copy or reverse engineer aspects of our products or to obtain and use information that we regard as proprietary. Policing unauthorized use of our products is difficult, and we cannot be certain that the steps we have taken will prevent misappropriation of our intellectual property. This is particularly true in foreign countries where the laws may not protect proprietary rights to the same extent as the laws of the United States and may not provide us with an effective remedy against unauthorized use. If our protection of our intellectual property proves to be inadequate or unenforceable, others may be able to use our proprietary developments without compensation to us, resulting in potential cost advantages to our competitors.

We may incur substantial expenses defending ourselves against claims of infringement.

        There are numerous patents held by many companies relating to the design and manufacture of network security systems. Although we are not aware of any instances in which our products violate the intellectual property rights of others or inappropriately use their technology, it is possible that third parties in the future may claim that our products infringe on their intellectual property rights. Any claim, with or without merit, could consume our management's time, result in costly litigation, cause delays in sales or implementations of our products or require us to enter into royalty or licensing agreements. Royalty and licensing agreements, if required and available, may be on terms unacceptable to us or detrimental to our business. Moreover, a successful claim of product infringement against us or our failure or inability to license the infringed or similar technology on commercially reasonable terms could seriously harm our business.

Fluctuations in our quarterly revenues may cause the price of our common stock to decline.

        Our operating results have varied significantly from quarter to quarter in the past, and we expect our operating results to vary from quarter to quarter in the future due to a variety of factors, many of which are outside of our control. Although our revenues are subject to fluctuation, significant portions of our expenses are not variable in the short term, and we cannot reduce them quickly to respond to decreases in revenues. Therefore, if revenues are below our expectations, this shortfall is likely to adversely and disproportionately affect our operating results. Accordingly we may not attain positive operating margins in future quarters. Any of these factors could cause our operating results to be below the expectations of securities analysts and investors, which likely would negatively affect the price of our common stock.



The price of our common stock has been volatile in the past and may continue to be volatile in the future due factors outside of our control.

        The market price of our common stock has been highly volatile in the past and may continue to be volatile in the future. For example, since June 1, 2003, the market price of our common stock on The Nasdaq SmallCap Market has fluctuated between $1.06 and $5.54 per share. The market price of our common stock may fluctuate significantly in response to a number of factors, many of which are outside our control, including:


Our recent reductions in our work force may make it more difficult for us to attract and retain the personnel necessary to successfully operate our business.

        We rely upon the continued service of a relatively small number of key technical, sales and senior management personnel. Our future success depends on retaining our key employees and our continuing ability to attract, train and retain other highly qualified technical, sales and managerial personnel. We have employment agreements with relatively few of our key technical, sales and senior management personnel. As a result, our employees could resign with little or no prior notice. We may not be able to attract, assimilate or retain other highly qualified technical, sales and managerial personnel in the future, especially given our recent reductions in force. The loss of any of our key technical, sales and senior management personnel or our inability to attract, train and retain additional qualified personnel could seriously harm our business.

Certain rights of the holders of 5% convertibleour preferred stock may hinder our ability to raise additional financing.

        We cannot issue shares of capital stock with rights senior to those of our existing 5% preferred stock or Series 2 5% preferred stock without the approval of at least a majority of the holders of our 5% preferred stock and all of the holders of our Series 2 5% preferred stock, voting or acting as separate classes. We also cannot incur certain indebtedness without the approval of at least a majority of the holders of our 5% convertible preferred stock. In addition, holders of the Series 2 5% preferred stock who are not executive officers or directors have the right to purchase a pro rata portion of certain future issuances of securities by us. The combination of these provisions could hinder or delay our ability to raise additional debt or equity financing.



You will experience substantial dilution upon the conversion or redemption of the shares of preferred stock and exercise of warrants that we issued in aour recent private placement.placements.

        On March 25, 2004, we completed a $5,000,000 private placement in connection with which we issued 1,000,000 shares of our 5% Convertible Preferred Stock and warrants to acquire 556,619 shares of our common stock. The conversion price for the preferred stock and the exercise price of the warrants is $3.144 per share. We also issued our placement agent a warrant for 64,408 shares of our common stock at an exercise price of $3.144 per share. As of May 13, 2005, there were 389,088 shares of 5% preferred stock, representing approximately 618,779 shares of common stock upon conversion, and warrants to purchase 556,619 shares of common stock outstanding.

        In addition, on March 28, 2005, we completed a $2,663,000 private placement in connection with which we issued 1,065,200 shares of our Series 2 5% Convertible Preferred Stock and warrants to acquire 532,600 shares of our common stock. We also issued two affiliates of our placement agent warrants to purchase an aggregate of 60,390 shares of common stock. The conversion price for the preferred stock is $2.50 per share and the exercise price of the warrants is $2.77 per share.

        On May 13, 2005, we had 6,138,030 shares of common stock outstanding. As a result, we expect the private placementplacements to result in a further dilution to holders of our common stock upon conversion of the preferred stock and exercise of the warrants of 2,221,3582,897,996 shares of common stock, or an approximately 43%47.2% increase in the number of shares of our common stock outstanding.

        Further, the occurrence of certain specified events described below under "Description of Securities and Related Transactions—Terms of the Series 2 5% Convertible Preferred Stock—Redemption" entitle holders of our Series 2 5% preferred stock to require us to redeem their shares for a number of shares of our common stock equal to the redemption price divided by 75% of the ten-day average of the volume weighted average price of our common stock ending on the day immediately preceding the holder's election to redeem. The redemption price for the shares of Series 2 5% preferred stock equals the sum of (1) the greater of $3.25 and the volume weighted average price of our common stock on the trading day immediately preceding the redemption event multiplied by $2.50 divided by the conversion price of the Series 2 5% preferred stock then in effect plus (2) any accrued but unpaid dividends on the Series 2 5% preferred stock plus (3) any unpaid liquidated damages or other amounts payable to the holders of the Series 2 5% preferred stock. As a result, assuming we have paid all liquidated damages and other amounts to the holders, accrued but unpaid dividends, on May 13, 2005 of



$17,145.34, a volume weighted average price of $2.26, which was the closing price of our common stock on May 13, 2005, and our 6,138,030 shares of common stock outstanding on May 13, 2005, we would issue approximately 2,052,534 shares of our common stock if a specified redemption event occurs and all holders of Series 2 5% preferred stock elected to redeem their shares for common stock. This would represent an increase of approximately 33.4% in the number of shares of our common stock as of May 13, 2005.

The conversion of preferred stock or exercise of warrants we issued in theour recent private placementplacements may cause the price of our common stock to decline.

        Upon the effectivenessThe holders of the registration statement related to this prospectus, the holdersshares of 5% preferred stock and warrants we issued in the private placement will be able toon March 25, 2004, may freely convert their shares of preferred stock and exercise their warrants and sell theirthe underlying shares of common stock pursuant to an effective registration statement we filed on August 6, 2004. As of May 13, 2005, 610,912 shares of 5% preferred stock had converted into 971,551 shares of common stock. In addition, upon the effectiveness of the registration statement related to this prospectus, the investors in our March 28, 2005 private placement would be able to freely sell the shares of common stock underlying their shares of Series 2 5% preferred stock and warrants we issued to them in that private placement upon the conversion of their shares and exercise of their warrants.

        For the four weeks ended on July 16, 2004,May 13, 2005, the average daily trading volume of our common stock on The NasdaqNASDAQ SmallCap Market was 5,06136,285 shares. Consequently, if holders of preferred stock or warrants elect to convert their remaining shares or exercise their warrants and sell a material amount of their underlying shares of common stock on the open market, the increase in selling activity could cause a decline in the market price of our common stock. Furthermore, these sales, or the potential for these sales, could encourage short sales, causing additional downward pressure on the market price of our common stock.

The percentage of our revenues attributable to sales of PDS products integrated with software of Check Point Software Technologies decreased from 29.1% in 2002 to 16.7% in 2003 and from 25.7% for the first quarter of 2003 to 4.6% for the first quarter of 2004. Because sales of our newer products may not offset the reduced sales of our PDS products, a change in our relationship with Check Point could have a negative effect on our operating results.

        Our PDS family of security appliances, which are integrated with Check Point Software Technologies' market-leading VPN-1®/FireWall-1® software, represented 4.6% of our revenues for the quarter ended March 31, 2004, and 16.7% of our revenues for the year ended December 31, 2003. These percentages are down from 25.7% of our revenues for the quarter ended March 31, 2003, and 29.1% of our revenues for the year ended December 31, 2002. We expect the percentage of our sales attributable to our PDS products to decline in the future; however, our reliance on newer product sales may not replace the anticipated decline in revenue from sales of our PDS products. Although we are a certified appliance partner of Check Point and our PDS products have received Check Point certification, we have no long-term agreement or exclusive relationship with Check Point. As a result, the loss or significant change in our relationship with Check Point, the failure of our PDS products to maintain or receive Check Point certification, the business failure of Check Point or its acquisition by or of one of our competitors and the loss of market share of Check Point or market acceptance of its products could each have a material adverse effect on our business, financial condition and results of operations.



Our acquisition of complementary products or businesses may adversely affect our financial condition.

        We have made acquisitions in the past, and, in the future, we may acquire or invest in additional companies, business units, product lines or technologies to accelerate the development of products and sales channels complementary to our existing products and sales channels. Negotiation of potential acquisitions and integration of acquired products, technologies or businesses could divert our management's time and resources. Future acquisitions could cause us to issue equity securities that would dilute your ownership of us, incur debt or contingent liabilities, amortize intangible assets or write off in-process research and development, goodwill and other acquisition-related expenses that could seriously harm our financial condition and operating results. Further, if we are not able to properly integrate acquired products, technologies or businesses with our existing products and operations, train, retain and motivate personnel from the acquired business or combine potentially different corporate cultures, we may not receive the intended benefits of our acquisitions, which could adversely affect our business, operating results and financial condition.

The payment of accrued dividends on our 5% convertible preferred stock may strain our cash resources.

        Shares of our 5% convertible preferred stock accrue cash dividends equal to $0.25 per share per annum. These dividends areannum, payable in arrears on March 31 and September 30 of each year, commencingand shares of our Series 2 5% convertible preferred stock accrue cash dividends equal to $0.125 per share per annum, payable in arrears on the first business day of March, June, September 30, 2004.and December of each year. The amount of the dividends on our Series 2 5% preferred stock may increase to $0.45 per share per annum upon the occurrence of certain event entitling the holders of these shares to redemption.

        During 2004, we paid $129 thousand in dividends related to our 5% convertible preferred stock and at May 13, 2005, we have dividends accrued of $11,459.44 related to our 5% preferred stock and $17,145.34 related to our Series 2 5% preferred stock.

        Delaware law provides that we may only pay dividends out of our capital surplus or, if no surplus is available, out of our net profits for the fiscal year the dividend is declared and/or the preceding fiscal year. We have not had net profits for the last two fiscal years, and as of MarchDecember 31, 2004 our2004. However, we did have sufficient capital surplus, defined as the amount by which our net assets exceed our stated capital, was approximately $2.7 million. Therefore,based on par value of our outstanding shares as provided by Delaware law. Although we are currently able to pay accrued dividends on our outstanding shares of preferred stock, we cannot assure you that our net assets will continue to exceed our stated capital or that we will have only limited resourcesnet profits in order to pay these dividends.dividends in the future. These dividends continue to accrue on our outstanding shares of preferred stock, regardless of whether we are legally able to pay them. The accrual of these dividends may adversely affect our operating results. In addition, the payment of these dividends could strain our available cash resources, which could adversely affect our ability to operate or grow our business.

Compliance with export regulations may hinder Furthermore, our sales to foreign customers.

        Certain of our data security products incorporate encryption and other technology that may require clearance and export licenses from the U.S. Department of Commerce under United States export regulations. Any inability to obtain these clearances or licenses or any foreign regulatory approvals, if required, on a timely basispay dividends could delay sales and have a material adverse effect on our operating results.

Provisions of our charter documents and Delaware law may have anti-takeover effects.

        Certain provisions of our certificate of incorporation and bylaws, such asadversely affect our ability to offer "blank check" preferred stock andraise equity financing in the inability of our stockholders to act by written consent, could make it more difficult for a third party to acquire us, evenfuture if doing so would be beneficial to our stockholders. We are also subject to the provisions of Section 203 of the Delaware General Corporation Law, which restricts certain business combinations with interested stockholders and could inhibit a non-negotiated merger or other business combination.

Our management and larger stockholders exercise significant control over our company and may approve or take actions that may be adverse to your interests.

        As of May 31, 2004, our executive officers, directors and 5% stockholders beneficially own approximately 38.5% of our voting power. As a result, these stockholders will be able to exercise significant control over all matters requiring stockholder approval, including the election of directors and approval of significant corporate transactions, which could delay or prevent someone from acquiring or merging with us. These stockholders may use their influence to approve or take actions that may be adverse to your interests.required.



Our management may spend the proceeds of this offering in ways with which you do not agree.

        Our management will have broad discretion over how we use the net proceeds of this offering and could spend proceeds in ways with which you do not agree. Pending deployment of the funds, the proceeds may be invested in ways that do not yield favorable returns. Please see the "Use of Proceeds" section of this prospectus for information about how we plan to use the proceeds of this offering.



NOTE REGARDING FORWARD-LOOKING STATEMENTS

        This prospectus and the materials incorporated herein by reference contain forward-looking statements that involve substantial risks and uncertainties. You can identify these statements by forwarding-looking words such as "may," "will," "expect," "intend," "anticipate," "believe," "estimate," "continue" and other similar words. You should read statements that contain these words carefully because they discuss our future expectations, make projections of our future results of operations or of our financial condition or state other "forward-looking" information. We believe that it is important to communicate our future expectations to our investors. However, there may be events in the future that we are not able to accurately predict or control. Our actual results could differ materially from the expectations we describe in our forward-looking statements as a result of certain factors, as more fully described in the "Risk Factors" section of this prospectus and the section entitled "Factors That May Affect Future Results of Operations" and elsewhere in the documents we file with the SEC that are incorporated herein.




DESCRIPTION OF SECURITIES AND RELATED TRANSACTIONS

Private Placement

        On March 25, 2004,28, 2005, we completed a private placement under Rule 506 of Regulation D with sixnine institutional investors and three individual accredited investors, including G. Ward Paxton, our Chairman, President and Chief Executive Officer, and James F. Gero, a member of our Board of Directors, pursuant to which the investors paid us an aggregate of $5,000,000$2,663,000 in consideration for (1) 1,000,0001,065,200 shares of our Series 2 5% convertible preferred stock convertible into shares of our common stock at an initial conversion price of $3.144$2.50 per share and (2) warrants to purchase up to 556,619532,600 shares of our common stock at an initial exercise price of $3.144$2.77 per share. The conversion price of the preferred stock and the exercise price of the warrants are subject to adjustments for stock dividends, splits, combinations, reclassifications and similar transactions.

        PursuantAs a condition to the termsconsummation of the Securities Purchase Agreement entered into in connection with the private placement, we granted each investor, other than Mr. Paxtonof our officers and Mr. Gero, who continuesdirectors executed a voting agreement pursuant to ownwhich they have agreed to vote the shares owned by them in favor of preferred stock priorany proposal to the sale, the right to purchase a pro rata portion of certain future sales of securities by us based on the ratiostockholders requesting an approval of the numberissuance of more then 1,211,605 shares of our common stock, held by that eligible investor, including any shareswhich represents 19.999% of our common stock issuableoutstanding as of March 28, 2005, upon the conversion of the shares of preferred stock and the exercise of the warrants owned by that eligible investor,we issued in this private placement, to the total number of shares of our common stock outstanding immediately prior to the sale, assuming the conversion of outstanding preferred stock and the exercise of the outstanding warrants. However, if the future saleextent this approval is at a price below the average trading price of our common stock for the ten days preceding the sale, each of the eligible investors will have the right to purchase a pro rata portion of the new securities based on the ratio of the number of shares of common stock ownedrequired by that eligible investor, assuming the conversion of the preferred stock and the exercise of the warrants owned by that investor, to the total number of shares of common stock then owned by all the eligible investors, assuming the conversion of all outstanding preferred stock and the exercise of all outstanding warrants. As a result, eligible investors will have the right to purchase 100% of the securities we offer to sell at below market price.Nasdaq rules.

        The investors' right of purchase will not apply to the following issuances by us, regardless of whether these issuances are below market price:

Compensation of Placement Agent

        Black Point Partners,Stonegate Securities, Inc. acted as our placement agent for thethis private placement financing.placement. As compensation for services rendered to us by Black Point Partners,Stonegate, we agreed to:


        We issued the warrantwarrants to Black Point Partnerstwo affiliates of Stonegate pursuant to Rule 506 of Regulation D. The terms ofOn May 17, 2005, these affiliates transferred their warrants and the underlying shares covered by this warrant are described below in "Termsprospectus to Crestview Capital Master LLC.

Terms of the Warrants-Black Point Partners Warrants."

Terms of theSeries 2 5% Convertible Preferred Stock

        Dividends.    Holders of the Series 2 5% preferred stock are entitled to a 5% per annum dividend per share. The dividend accrues and is payable in cash semi-annuallyquarterly on the lastfirst business day of March, June, September and September.December of each year, beginning on June 1, 2005. Dividends may increase to 18% per annum upon the occurrence of certain redemption events described below under "Terms of the Series 2 5% Convertible Preferred Stock-Redemption".

        Accrued but unpaid dividends are also payable upon the conversion or redemption of the shares of preferred stock and upon a liquidation event. Dividends not paid within five business days of the day they are due accrue daily interest at the lesser of 18% per annum or the maximum rate permitted by law, until the dividends and the accrued interest are paid in cash.

        As long as any shares of the Series 2 5% preferred stock are outstanding, we cannot pay dividends or make other distribution on, redeem shares of, or set money aside or create a sinking fund for that purpose for, any shares of capital stock ranking junior to the Series 2 5% preferred stock with respect to dividends, including our common stock. However, this restriction does not apply to the payment of accrued dividends on our existing 5% convertible preferred stock or the conversion of any of our convertible capital stock in accordance with its terms.

        Voting Rights.    Holders of preferred stock will vote together with shares of common stock on an as converted to common stock basis. Based on the conversion rate of the preferred stock holders of shares of preferred stock will receive 1.5903 votes for each share. After aggregating allhave no voting rights, of a particular holder, any fractional votes are rounded to the nearest whole number. As a result, a holder of 100 shares of preferred stock would be entitled to 159 votes on any matters submitted to our stockholders for approval.

        In addition,except as required by law. However, as long as any shares of the Series 2 5% preferred stock areremain outstanding, we cannot take



any of the following actions without the separate class vote or written consent of a majorityall of the then outstanding shares of the Series 2 5% preferred stock:

        Conversion.    The holders of the Series 2 5% preferred stock which is comprised of an aggregate of 1,000,000 authorized shares, is convertible, athave the option of the holders,to convert their shares into shares of our common stock at an initial conversion price of $3.144$2.50 per share. BasedWe also have the right to force conversion of outstanding shares of the Series 2 5% preferred stock after March 28, 2006, if the following conditions are met:

        Because the original purchase price of $5.00 per share,and the initial conversion price are the same, each share of Series 2 5% preferred stock is initially convertible into 1.5903 sharesone share of our common stock. The Series 2 5% preferred stock contains adjustment provisions upon the occurrence of stock splits, stock dividends, combinations, reclassifications or similar events of our capital stock as well as any rights offering or pro rata distribution of cash, property, assets or securities to holders of our common stock.



        A holder of Series 2 5% preferred stock cannot convert their shares of preferred stock into shares of our common stock if that holder would beneficially own greater than 9.9%4.99% of our issued and outstanding shares of common stock, as determined in accordance with Section 13(d) of the Exchange Act, upon conversion. However, this restriction does not apply to any holder of Series 2 5% preferred stock who is one of our directors or officers. Although this restriction does not limit the conversion of the shares of Series 2 5% preferred stock.



        Redemption.    We havestock purchased by Mr. Paxton or Mr. Gero, neither Mr. Paxton nor Mr. Gero may convert their shares into common stock unless and until the rightissuance is approved by our stockholders to redeem any orthe extent required by Nasdaq rules.

        In addition, we cannot issue shares to a holder of Series 2 5% preferred stock if the number of shares issuable upon conversion of all shares of Series 2 5% preferred stock added together with the number of shares issuable upon the exercise of the outstandingprivate placement warrant exceeds 1,211,605 shares, of preferred stock at a price of $5.00 per share plus any accrued but unpaid dividends at any time after September 25, 2004 if the following conditions are met:

stockholders under Nasdaq Marketplace Rule 4350.

        Rank; Liquidation Preference.    The holders of Series 2 5% preferred stock rank prior to the holders of our common stock and unless otherwise consented to by the holders ofexisting 5% preferred stock prior to all other classes of capital stock currently outstanding, or that we may establish, with respect to the distribution of our assets upon a bankruptcy,dissolution, liquidation or other similar event. The liquidation preference for the Series 2 5% preferred stock is an amount equal to $5.00$2.50 per share plus any accrued andbut unpaid dividends.

        In addition to a dissolution, liquidation or similar event, the following "change of control" transactions constitute a liquidation:

        Redemption.    Holders of Series 2 5% preferred stock can require us to redeem all of their shares of upon the occurrence of any of the following events:


        The redemption price is the sum of (1) the greater of $3.25 and the product of the volume weighted average price of our common stock on the trading day immediately preceding the event multiplied by $2.50 divided by the conversion price then in effect plus (2) any accrued but unpaid dividends on the Series 2 5% preferred stock plus (3) all liquidated damages or other amounts payable to the holders of Series 2 5% preferred stock. The redemption price is payable in cash if a redemption event occurs as a result of our failure to deliver stock certificates upon conversion, our public announcement of our refusal to comply with conversion requests, our failure to pay damages to a holder who is forced to cover a sale for which we did not timely issue certificates, our breach of the provisions of any of the agreements executed in connection with the private placement, our becoming party to a change of control transaction or our voluntary bankruptcy. In the case of any other redemption event, a holder has the option to receive a number of shares of our common stock equal to the redemption price divided by 75% of the ten-day average of the volume weighted average price of our common stock ending on the day immediately preceding the holder's election or an increase in the dividends payable per share to 18% per annum. Prior to receiving any requisite stockholder approval for the issuance of additional shares, holders may only elect to increase the dividend. In addition, Mr. Paxton and Mr. Gero will not be able to receive stock upon redemption of their shares unless and until the issuance is approved by our stockholders to the extent required by Nasdaq rules. Payment of the redemption price is due within five trading days after the holder provides us with a notice of payment, after which the unpaid amount accrues interest daily at a rate equal to the lower of 18% per annum and the highest rate permitted by law.

Terms of the Warrants

        Private Placement Warrants.    The warrants we issued in the private placement have an initial exercise price of $3.144$2.77 per share and are exercisable for our common stock at any time during the period commencing on September 28, 2005 and ending on or before September 28, 2010. The warrants contain a cashless exercise provision, permitting the holder at any time on or after March 28, 2006, in lieu of paying the exercise price, to surrender the warrant for a number of shares of common stock determined by multiplying the number of shares of common stock underlying the warrant by a fraction based on the exercise price of the warrant and the volume weighted average price of our common stock on trading day immediately preceding the exercise date. A holder may only use the cashless exercise if there is no effective registration statement covering the resale of the shares of common stock underlying the warrant at the time the holder wishes to exercise.

        All of the warrants contain adjustment provisions upon the occurrence of stock splits, stock dividends, combinations, reclassification or similar events of our capital stock as well as pro rata distributions of cash, property, assets or securities to holders of our common stock.



        A holder of a warrant cannot exercise warrants for shares of our common stock if that holder would beneficially own greater than 4.99% of our issued and outstanding shares of common stock, as determined in accordance with Section 13(d) of the Exchange Act, upon exercise of the warrants. However, this restriction does not apply to any holder of a warrant who is one of our directors or officers. Although this restriction does not currently limit the exercise of the warrants acquired by Mr. Paxton or Mr. Gero, neither Mr. Paxton or Mr. Gero may exercise their warrants for common stock unless the issuance is approved by our stockholders to the extent required by Nasdaq rules.

        In addition, we cannot issue shares of common stock upon the exercise of a warrant if the number of shares to be issued upon the exercise of all of the private placement warrants added together with the number of shares issuable upon the conversion of the Series 2 5% preferred stock, exceeds 1,211,605, or 19.999% of our outstanding shares of common stock on March 28, 2005, unless we have received the requisite approval of our stockholders under Nasdaq Marketplace rule 4350.

        Stonegate Warrants.    The warrants we originally issued to the affiliates of Stonegate have an initial exercise price of $2.77 per share and are exercisable for our common stock at any time on or before March 25, 2009. The warrants contain28, 2010. Each warrant contains a cashless exercise provision, permitting the holder, in lieu of paying the exercise price, to surrender the warrant for a number of shares of common stock determined by multiplying the number of shares of common stock underlying the warrant by a fraction based on the exercise price of the warrant and the current market value of our common stock.

        All of theThe warrants contain adjustment provisions upon the occurrence of stock splits, stock dividends, combinations, reclassification or similar events of our capital stock.

        A holderPre-emptive Rights and Restrictions on Future Sales of Equity

        Pre-emptive Rights.    Pursuant to the terms of the Securities Purchase Agreement entered into in connection with the private placement, we granted the investors, other than Mr. Paxton and Mr. Gero, who continue to own shares of preferred stock prior to the sale, the right to purchase up to 100% of the securities we may offer in certain future sales of securities within 180 days of the effective date of the registration statement relating to this prospectus.

        The investors' right of purchase will not apply to the following issuances by us:

        Restrictions of Future Sales.    The Securities Purchase Agreement also restricts us from issuing any shares of common stock or other securities convertible or exercisable for common stock until the date that is 180 days after the effective date of the registration statement relating to this prospectus. In addition, as long as any investor holds Series 2 5% preferred stock or warrants, we cannot exercise warrantsissue debt or



equity securities that are convertible or exercisable for shares of common stock at a price that varies with the trading price of our common stock if that holder would beneficially own greater than 9.9% ofor is subject to reset for events contingent on our issued and outstanding shares of common stock, as determined in accordance with Section 13(d) ofbusiness or the Exchange Act, upon exercise of the warrants.

        Black Point Partners Warrant.    The warrant we issued to Black Point Partners has an initial exercise price of $3.144 per share and is exercisable for our common stock or enter into any other agreement, including an equity line of credit, pursuant to which we sell securities at any time on or before March 25, 2009. The warrant contains a cashless exercise provision, permitting Black Point Partners, in lieu of payingfuture determined price. However, these restrictions do not apply to transactions which are exempt from the exercise price, to surrender the warrant for a number of shares of common stock determined by multiplying the number of shares of common stock underlying the warrant by a fraction based on the exercise price of the warrant and the current market value of our common stock.pre-emptive rights described above.

        The warrant contains adjustmentThese provisions upon the occurrence of stock splits, stock dividends, combinations, reclassificationmay hinder or similar events ofdelay our ability to raise additional debt or equity financing if and when we require additional capital stock.to operate or grow our business.



Registration Rights

        In connection with the Securities Purchase Agreement, we entered into a Registration Rights Agreement, pursuant to which we are required to file a registration statement to register the 2,146,9501,597,800 shares of common stock issuable upon the conversion of the preferred stock and upon the exercise of the warrants issued to the investors in the private placement. This prospectus relates to the registration of all of these shares of common stock. If Under the terms of the Registration Rights Agreement, we may be subject to the payment of partial liquidated damages if any of the following events occurs:

        The amount of liquidated damages will equal to 2%1% of the aggregate purchase price paid to us by the investors in the private placement for eachthe first thirty-day period, and 2% of the aggregate purchase price for each subsequent thirty-day period, each pro rated for any shorter period, that the filing or effectivenessfollowing any of the registration statement is delayed.

        This prospectus also includes 337,338 shares previously acquired by Gryphon Master Fund, L.P., oneabove events. The damages are payable on the monthly anniversary of the investors, 125,000 shares previously acquired by Mr. Gero, onedate of our directors and an investor,the event giving rise to the damages. Any damages not paid within seven days of the date due will accrue daily interest at the lesser of 18% per annum and the 64,409maximum amount permitted by law until paid in full. No damages are payable to Crestview Capital Master LLC with respect to the shares of common stock underlying the warrant we issuedwarrants it acquired from the affiliates of Stonegate or to Black Point Partners.

        As a condition to the consummation of the private placement, eachany person who is one of our executive officers or directors at the time the payment is due. Therefore, Mr. Paxton and directors has agreedMr. Gero are not currently entitled to sellreceive any shares of our common stock owned by them until the registration statement relating to this prospectus is declared effective.these damages.

        We must keep the registration statement related to this prospectus effective until the earliestearlier to occur of March 25, 2006,the date when all the securities covered by the registration statement may be sold without restriction pursuant to Rule 144(k) and the date on which all shares of common stocksecurities covered by the registration statement are sold and the termination of the registration rights agreement.have been sold.




PLAN OF DISTRIBUTION

        Shares of our common stock held by the selling stockholders and covered by this prospectus may be sold or distributed at any time or from time to time by the selling stockholders, their pledgees, donees, transferees or other successors in interest, in one or more transactions. The selling stockholders will act independently of us in making decisions with respect to the timing, manner and size of each sale. The selling stockholders may sell their shares at market prices prevailing at the time of sale, at prices related to the then current market price, at varying prices determined at the time of sale in negotiated transactions, or at such other price as the selling stockholders may determine from time to time.

        The selling stockholders may offer their shares at various times in one or more of, or a combination of, the following or other kinds of transactions:

        No selling stockholder had any agreement or understanding, directly or indirectly, with any person to distribute the shares underlying the preferred stock and warrants at the time the selling stockholder purchased them. All of the selling stockholders purchased the securities in the ordinary course of business.

        If the selling stockholders effect these transactions by selling shares to or through broker-dealers or agents, those broker-dealers or agents may receive compensation in the form of commissions, discounts or concessions from selling stockholders or commissions from purchasers of the shares for whom they may act as agent. These commissions, discounts or concessions as to a particular broker-dealers or agents may be in excess of customary commissions in the types of transactions involved. Broker-dealers or agents and any other participating broker-dealers or the selling stockholders may be deemed to be "underwriters" within the meaning of Section 2(11) of the Securities Act in connection with sales of the shares. Because selling stockholders may be deemed to be "underwriters" within the meaning of Section 2(11) of the Securities Act, the selling stockholders will be subject to the prospectus delivery requirements of the Securities Act. The selling stockholders have not entered into any agreements, understandings or arrangements with any underwriters or broker-dealers with respect to the sale of the shares covered by this prospectus.



        The selling stockholders may enter into hedging transactions with broker-dealers or other financial institutions in connection with distributions of the shares or otherwise. In these transactions, broker-dealers or other financial institutions may engage in short sales of the shares in the course of hedging the positions they assume with selling stockholders. The selling stockholders also may sell shares short and redeliver the shares to close out short positions. Several of the selling stockholders have entered



into sort positions as of the date hereof. None of the shares issuable upon conversion of the preferred stock or exercise of the warrants and none of the other shares described in this prospectus will be used to cover any of these short positions or any other short positions prior to the effectiveness of the registration statement relating to this prospectus. The selling stockholders may enter into option or other transactions with broker-dealers or other financial institutions which require the delivery to the broker-dealer or financial institutions of the shares. The broker-dealer or other financial institutions may then resell or otherwise transfer those shares pursuant to this prospectus.

        The selling stockholders also may loan or pledge the shares to a broker-dealer. The broker-dealer or other financial institutions may sell the shares so loaned, or upon a default the broker-dealer may sell the pledged shares pursuant to this prospectus.

        Under the securities laws of certain states, the shares may be sold in those states only through registered or licensed brokers or dealers. In addition, in certain states the shares may not be sold unless they have been registered or qualified for sale in the applicable state or an exemption from the registration or qualification requirement is available and is complied with.

        Selling stockholders may also resell all or a portion of the shares in open market transactions in reliance upon Rule 144 under the Securities Act, rather than under this prospectus, provided they meet the criteria and conform to the requirements of such rule.

        Under applicable rules and regulations under the Exchange Act, any person engaged in the distribution of the shares may not simultaneously engage in market making activities with respect to our common stock until his or her participation in that distribution is completed. In addition, each selling stockholder will be subject to applicable provisions of the Exchange Act and the associated rules and regulations under the Exchange Act, including Regulation M, which provisions may limit the timing of purchases and sales of shares of common stock by the selling stockholders.

        We will make copies of this prospectus available to the selling stockholders. We have informed them of the need for delivery of copies of this prospectus to purchasers at or prior to the time of any sale of the shares offered hereby. The selling stockholders may agree to indemnify any broker-dealer or agent that participates in transactions involving sales of the shares against certain liabilities, including liabilities under the Securities Act.

        At the time a particular offer of shares is made, we will file a supplement to this prospectus, if required, that will disclose:

        In addition, upon being notified by a selling stockholder that a donee or pledgee intends to sell more than 500 shares, we will file a supplement to this prospectus.

        We entered into the registration rights agreement described under "Description of Securities and Related Transactions—Registration Rights" for the benefit of the selling stockholders to register the shares of common stock under applicable federal and state securities laws. Pursuant to the terms of the registration rights agreement, we will pay all expenses of the registration of the shares except that the



selling stockholders will pay any applicable commissions and discounts attributable to the sales of the shares and costs and expenses of their own counsel. We have agreed to indemnify the selling stockholders against certain liabilities relating to the registration statement, including liabilities under the Securities Act. Conversely, each selling stockholder has agreed to indemnify us against certain liabilities relating to the information given to us in writing by that selling stockholder for inclusion in the registration statement, including liabilities under the Securities Act.




USE OF PROCEEDS

        We will receive the exercise price of the warrants, if they are exercised for cash, but will receive no proceeds from the resale of the underlying shares which may be offered hereby. As of the date of this prospectus, if all of the warrants for which we are registering the underlying shares of our common stock are exercised for cash, we would receive an aggregate of approximately $1,952,512.03.$1,642,582.30. We intend to use the proceeds, if any, from the exercise of the warrants for general corporate purposes and working capital.





SELLING STOCKHOLDERS

        The following table identifies each of the selling stockholders and sets forth information as of the date of this prospectus with respect to the number of shares which may be offered under this prospectus from time to time by each selling stockholder. This information includes shares obtainable upon conversion or exercise of shares of preferred stock and warrants, which are currently convertible or exercisable into shares of our common stock. Except as otherwise indicated, the persons named in the table below have sole investment and voting power with respect to all shares beneficially owned, subject to community property laws, where applicable. Percentage ownership is based on 5,166,3126,138,030 shares of our common stock outstanding on July 22, 2004 and reflects a four-for-one (4:1) reverse split of our common stock effective March 29, 2004.May 13, 2005. For purposes of this table, the shares of common stock beneficially owned by a person or group of persons before the offering equals the sum of:

        Under the terms of the Series 2 5% preferred stock and warrants we issued in the private placement, the shares of Series 2 5% preferred stock are convertible and the warrants are exercisable by any selling stockholder who participated in the private placement only to the extent that the number of shares of common stock issuable pursuant to those securities, together with the number of shares of our common stock owned by that selling stockholder and its affiliates (but not including shares of common stock underlying unconverted portions of the Series 2 5% preferred stock or unexercised portions of the warrants) would not exceed 9.9%4.99% of the then outstanding common stock as determined in accordance with Section 13(d) of the Exchange Act. However, this restriction does not apply to any holder of Series 2 5% preferred stock or warrants who is one of our directors or officers. Although this restriction does not currently limit the conversion of shares or the exercise of warrants by Mr. Paxton or Mr. Gero, neither Mr. Paxton nor Mr. Gero may convert their shares into, or exercise their warrants for, common stock unless the issuance is approved by our stockholders to the extent required by NASDAQ rules. In addition, we cannot issue shares of common stock to any selling stockholder who participated in the private placement upon the conversion of their shares or the exercise of their warrants if the number of shares to be issued upon the conversion of all of the shares of Series 2 5% preferred stock and all of the warrants we issued in the private placement exceeds 1,211,605, or 19.99% of our outstanding shares of common stock on March 28, 2005, unless we have received the requisite approval of our stockholders under Nasdaq Marketplace Rule 4350. Finally, the selling stockholders who participate in the private placement may not exercise their warrants until September 28, 2005. Accordingly, the number of shares of common stock set forth in the column "Shares Offered" in the table below for certain selling stockholders exceedsmay exceed the number of shares of common stock that the selling stockholder could beneficially own at any given time through the ownership of thesetheir shares or Series 2 5% preferred stock or warrants.

        All of the shares of common stock being offered by this prospectus are being offered by the selling stockholders for their own accounts. Because the selling stockholders may sell all, some or none of the shares covered by this prospectus, and there are currently no agreements, arrangements or understandings with any of the selling stockholders with respect to the sale of any of the shares, we



cannot estimate the number of shares or the percentage of outstanding shares of common stock, that will be held by any of them upon termination of this offering. For purposes of this table, we are assuming that the selling stockholders will sell all of the shares offered by this prospectus and will not acquire any additional shares.



        This prospectus also covers any additional shares of common stock which may become issuable in connection with shares sold by reason of a stock dividend, stock split, recapitalization or other similar transaction effected without us receiving any cash or other value, which results in an increase in the number of our outstanding shares of common stock.

        Of the 2,673,6971,658,190 shares of common stock being offered by the selling stockholders:

        Other than Black Point Partners, Mr. Gero and Mr. Paxton, none of the selling stockholders has had a material relationship with us within the past three years other than as a result of the ownership of shares or our common stock or other securities. See "Certain Relationships among the Selling Stockholders and Intrusion."

 
  
  
 Shares Owned
After the Offering

 
 
 Shares Beneficially Owned Before Offering
  
 
Name of Selling Stockholder

 Shares
Offered

 
 Number
 Percent
 
Black Point Partners, Inc.(1) 64,409 64,409 0 0.0%
Gero, James F. 318,430 253,817 64,613 0.9%
Gryphon Master Fund, L.P.(2) 831,136 831,136 0 0.0%
Paxton, G. Ward(3) 671,075 300,572 370,503 5.0%
Crestview Capital Master, L.L.C.(4) 343,512 343,512 0 0.0%
Enable Growth Partners, L.P.(5) 193,226 193,226 0 0.0%
Marshall B. Payne 42,940 42,940 0 0.0%
Renaissance Capital Growth & Income Fund III, Inc.(6) 214,695 214,695 0 0.0%
Renaissance US Growth Investment Trust PLC(6) 214,695 214,695 0 0.0%
BFS US Special Opportunities Trust PLC(6) 214,695 214,695 0 0.0%
Total 3,108,813 2,673,697 435,116 5.9%
  
 
 
 
 
 
 Shares
Beneficially
Owned
Before
Offering

  
 Shares Owned
After the Offering

 
Name of Selling Stockholder

 Shares
Offered

 
 Number
 Percent
 
Bluegrass Growth Fund LP(1) 30,000 30,000 0 0.0%
Bluegrass Growth Fund LTD(1) 30,000 30,000 0 0.0%
Bushido Capital Master Fund, LP(2) 150,000 150,000 0 0.0%
Crestview Capital Master LLC(3) 149,449 60,390 89,059 1.4%
Enable Growth Partners LP(4) 413,226 300,000 113,226 1.8%
Gamma Opportunity Capital Partners, LP(5) 150,000 150,000 0 0.0%
Gero, James F.(6) 410,930 90,000 320,930 5.1%
Nite Capital L.P.(7) 306,000 306,000 0 0.0%
Paxton, G. Ward(8) 910,995 240,000 670,995 10.4%
Payne, Marshall R.(9) 102,940 60,000 42,940 * 
TCMP3 Partners L.P.(10) 91,800 91,800 0 0.0%
Truk International Fund, LP(11) 9,000 9,000 0 0.0%
Truk Opportunity Fund, LLC(11) 141,000 141,000 0 0.0%
 Total(12) 2,895,340 1,658,190 1,237,150 18.2%
  
 
 
 
 

*
Less than 1%

Footnotes to Selling Stockholder Table:

(1)
Charles T. ManuelDeborah Solomon has voting and/or investment control over the shares held by Black Point Partners, Inc. Mr. ManuelBluegrass Growth Fund LP and Bluegrass Growth Fund LTD. Ms. Solomon disclaims beneficial ownership of these shares.

(2)
Gryphon Master Fund, L.P. has shared voting power and shared dispositive power over all of these shares with Gryphon Management Partners, L.P., Gryphon Partners, L.P., Gryphon Partners (QP), L.P., Gryphon Advisors, LLC and E.B. Lyon IV. Gryphon Partners, L.P. is the general partner of Gryphon Master Fund, L.P. Gryphon Management Partners, L.P. is the general partner of Gryphon Partners, L.P. Gryphon Advisors, LLC is the general partner of Gryphon Management Partners, L.P. Mr. Lyon controls Gryphon Advisors, LLC andChristopher Rossman has voting and/or investment control over the shares held by GryphonBushido Capital Master Fund, L.P.LP. Mr. LyonRossman disclaims beneficial ownership of these shares.

(3)
Includes 89,059 shares of our common stock issuable upon the exercise of existing warrants. Steve Halpern has voting and/or investment control over the shares held by Crestview Capital Master LLC. Mr. Halpern disclaims beneficial ownership of these shares.

(4)
Includes 63,130 shares of our common stock issuable upon the conversion of our 5% convertible preferred stock and 50,096 shares of our common stock issuable upon the exercise of existing warrants. Mitch Levine has voting and/or investment control over the shares held by Enable Growth Partners LP. Mr. Levine disclaims beneficial ownership of these shares.

(5)
Jonathan P. Knight and Christopher Rossman have voting and/or investment control over the shares held by Gamma Opportunity Capital Partners, LP. Mr. Knight and Mr. Rossman disclaim beneficial ownership of these shares.

(6)
Includes 95,419 shares of common stock issuable upon the conversion of our 5% convertible preferred stock and 33,397 shares of our common stock issuable upon the exercise of existing warrants. Also includes 2,501 shares that Mr. Gero may acquire upon the exercise of options that are currently exercisable or that will be exercisable within 60 days or May 13, 2005.

(7)
Keith Goodman has voting and/or investment control over the shares held by Nite Capital L.P. Mr. Goodman disclaims beneficial ownership of these shares.

(8)
Includes 222,646 shares of our common stock issuable upon the conversion of our 5% convertible preferred stock and 77,926 shares issuable upon the exertion of existing warrants. Also includes the equivalent of 5,0774,996 shares held by Mr. Paxton in the Intrusion Stock Fund in the Intrusion 401(k) Savings Plan.

(4)(9)
Stew FinkIncludes 31,807 shares of our common stock issuable upon the conversion of our 5% convertible preferred stock and Richard Levy11,133 shares of our common stock issuable upon the exercise of existing warrants.

(10)
Walter Schenker and Steven Slawson have voting and/or investment control over the shares held by Crestview Capital Master, L.L.C.TCMP3 Partners L.P. Mr. FinkSchenker and Mr. LevySlawson disclaim beneficial ownership of these shares.

(5)(11)
Mitch Levine hasMichael E. Fein and Stephen E. Saltzstein are principals of Atoll Asset Management, LLC, the managing member of Truk International Fund, LP and Truk Opportunity Fund, LLC. As a result, Mr. Fein and Mr. Saltzstein have voting or investment control over the shares held by Enable Growth Partners, L.P. Mr. Levine disclaims beneficial ownership of those shares.
(6)
RENN Capital Group, Inc. is the investment advisor or manager to Renaissance Capital Growth & Income Fund III, Inc., Renaissance US Growth Investment Trust PLC and BFS US Special Opportunities Trust PLC. Russell Cleveland is the president of RENN Capital Group, Inc. and has voting and/or investment control over the shares held by these entities.selling stockholders. Mr. Cleveland disclaimsFein and Mr. Saltzstein disclaim beneficial ownership of these shares.

(12)
See notes (3), (4), (6), (8) and (9).

Certain Relationships among the Selling Stockholders and Intrusion

Directors and Executive Officers

        The following selling stockholders are directors and, in one instance, an executive officer of our company:

Black Point Partners, Inc.

        Black Point Partners, Inc. acted as our financial advisor and exclusive placement agent in connection with the issuance of our 5% convertible preferred stock and warrants to the investors in the private placement. As compensation for acting as our placement agent, we paid Black Point Partners an aggregate of $200,000. In addition, we issued Black Point Partners a warrant to purchase an aggregate of 64,409 shares of our common stock at an exercise price of $3.144 per share.






LEGAL MATTERS

        The validity of the common stock offered hereby will be passed upon for us by Patton Boggs LLP, Dallas, Texas.


EXPERTS

        Our consolidated financial statements and schedule for the years ended December 31, 2002 and 2001 appearing in our Annual Report (Form 10-K) for the year ended December 31, 2003, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their report thereon included therein2004 and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

        Our consolidated financial statements and schedule for the year ended December 31, 2003, appearing in our Annual Report (Form 10-K)10-KSB) for the year ended December 31, 2003,2004, have been audited by KBA Group LLP, independent registered public accounting firm, as set forth in their report thereon included therein and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing.


WHERE YOU CAN FIND ADDITIONAL INFORMATION

        We file annual, quarterly and special reports, proxy statements and other information with the Securities and Exchange Commission. You may read and copy any document we file at the SEC's public reference room in Washington, D.C. Please call the SEC at 1-800-SEC-0330 for further information on the public reference rooms. Our SEC filings are also available to you without charge at the SEC's web site at http://www.sec.gov.

        The SEC allows us to "incorporate by reference" the information we file with them, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus, and later information filed with the SEC will update and supersede this information. We incorporate by reference the documents listed below and any future filings made with the SEC under Section 13a, 13(c), or 15(d) of the Securities Exchange Act of 1934 until our offering is completed.


        You may request a copy of these filings, at no cost, by writing or telephoning us at the following address:

        You should rely only on the information incorporated by reference or provided in this prospectus or the prospectus supplement. We have authorized no one to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus or the prospectus supplement is accurate as of any date other than the date on the front of the document.




        We have not authorized any person to make a statement that differs from what is in this prospectus. If any person does make a statement that differs from what is in this prospectus, you should not rely on it. This prospectus is not an offer to sell, nor is it seeking an offer to buy, these securities in any state in which the offer or sale is not permitted. The information in this prospectus is complete and accurate as of its date, but the information may change after that date.

Intrusion Inc.



2,673,6971,658,190 Shares
of Common Stock




PROSPECTUS




                        , 2004
2005





PART II
INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14.Other Expenses of Issuance and Distribution


  
 
SEC Registration Fees $1,143.31 SEC Registration Fees $429.37 
Legal Fees 70,000.00*Legal Fees 70,000.00*
Accounting Fees and Expenses 25,000.00*Accounting Fees and Expenses 10,000.00*
Printing Fees 10,000.00*Printing Fees 7,500.00*
Transfer Agent's Fees and Costs of Certificates 2,000.00*Transfer Agent's Fees and Costs of Certificates 2,000.00*
Placement Agent Fees 200,000.00 Placement Agent Fees 120,780.00 
Miscellaneous 10,000.00*Miscellaneous 10,000.00*
Total $318,143.31 
Total $220,709.37 

*
Estimated

ITEM 15.Indemnification of Directors and Officers

        Section 145 of the Delaware General Corporation Law (the "DGCL") provides, in effect, that any person made a party to any action by reason of the fact that he is or was our director, officer, employee or agent may and, in certain cases, must be indemnified by us against, in the case of a non-derivative action, judgments, fines, amounts paid in settlement and reasonable expenses (including attorneys' fees) incurred by him as a result of such action, and in the case of a derivative action, against expenses (including attorneys' fees), if in either type of action he acted in good faith and in a manner he reasonably believed to be in our not opposed to our best interests. This indemnification does not apply, in a derivative action, to matters as to which it is adjudged that the director, officer, employee or agent is liable to us, unless upon court order it is determined that, despite such adjudication of liability, but in view of all the circumstances of the case, he is fairly and reasonably entitled to indemnity for expenses, and, in a non-derivative action, to any criminal proceeding in which such person had reasonable cause to believe his conduct was unlawful.

        Article Six, Section 3 of our Certificate of Incorporation provides that no director shall be liable to us or our stockholders for monetary damages for breach of fiduciary duty as a director to the fullest extent permitted by the DGCL.

        We have entered into Indemnification Agreements with the each of our directors and executive officers. Pursuant to our agreements, we will be obligated, to the extent permitted by applicable law, to indemnify our directors and officers against all expenses, judgments, fines and penalties incurred in connection with the defense or settlement of any actions brought against them by reason of the fact that they were our directors or officers or assumed certain responsibilities at our direction. We also have purchased directors and officers liability insurance in order to limit our exposure to liability of indemnification of directors and officers.

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ITEM 16.Exhibits and Financial Statement Schedules

Exhibit Number
 Description

 

 

 

4.1

(1)

Form of 5% Convertible Preferred Stock Certificate.

4.2

(1)

Certificate of Designations of the 5% Convertible Preferred Stock of Intrusion Inc.

4.3

(1)

Form of Warrant for the Purchase of Shares of Common Stock.

4.4

(1)

Warrant to Purchase Shares of Common Stock dated March 25, 2004 by Intrusion Inc. in favor of Black Point Partners, Inc.

4.5

(1)

Form of Lock-Up Agreement executed by Intrusion Inc. and each of its executive officers and directors.

4.6

(1)

Registration Rights Agreement dated as of March 25, 2004 by and among Intrusion Inc. and the persons and entities listed on Exhibit A thereto.

5.1

(3)

Opinion of Patton Boggs LLP, regarding the legality of the securities covered by this registration statement.

10.1

(1)

Securities Purchase Agreement dated as of March 25, 2004, by and among Intrusion Inc. and the purchasers listed on Exhibit A thereto.

23.1

 

Consent of KBA Group LLP.

23.2

 

Consent of Ernst & Young LLP.

23.3

(3)

Consent of Patton Boggs LLP (included in its opinion filed as Exhibit 5.1).

24.1

(2)

Power of Attorney.
Exhibit Number

Description
4.1(1)Form of Series 2 5% Convertible Preferred Stock Certificate.
4.2(1)Certificate of Designations of the Series 2 5% Convertible Preferred Stock of Intrusion Inc.
4.3(1)Form of Common Stock Purchase Warrant issued to the investors in the private placement.

II-1


4.4(1)Form of Representative's Warrant for the Purchase of Shares of Common Stock issued to certain affiliates of Stonegate Securities, Inc.
4.5(1)Form of Voting Agreement executed by each of the executive officers and directors of Intrusion Inc.
4.6(1)Registration Rights Agreement dated as of March 28, 2005 by and among Intrusion Inc. and each of the purchasers listed on the signature pages thereto.
5.1(2)Opinion of Patton Boggs LLP, regarding the legality of the securities covered by this registration statement.
10.1(1)Securities Purchase Agreement dated as of March 28, 2005, by and among Intrusion Inc. and the investors listed on the signature pages thereto.
10.2(1)Placement Agency Agreement dated February 7, 2005, by and between Intrusion Inc. and Stonegate Securities, Inc.
23.1Consent of KBA Group LLP.
23.2(2)Consent of Patton Boggs LLP (included in its opinion filed as Exhibit 5.1).
24.1(2)Power of Attorney.

(1)
Incorporated herein by reference to the Registrant's Current Report on Form 8-K dated March 25, 2004.29, 2005.

(2)
Previously filed with the Registrant's Registration Statement on Form S-3 filed on April 20, 2004.
(3)
Previously filed with the Registrant's Amendment No. 1 to Registration Statement filed on June 14, 2004.22, 2005.

ITEM 17.Undertakings

        The Registrant hereby undertakes:

        (1)   To file, during any period in which offers or sales of securities are being made, a post-effective amendment to this registration statement:

II-2


provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed with or furnished to the Commission by the registrant pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement.

        (2)   That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

II-2



        (3)   To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

        The Registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the Registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan's annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initialbona fideoffering thereof.

        Insofar as indemnification for liabilities arising under the Securities Act, may be permitted to directors, officers and controlling persons of Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

II-3



INDEX TO EXHIBITS

Exhibit Number
 Description

 

 

 

4.1

(1)

Form of 5% Convertible Preferred Stock Certificate.

4.2

(1)

Certificate of Designations of the 5% Convertible Preferred Stock of Intrusion Inc.

4.3

(1)

Form of Warrant for the Purchase of Shares of Common Stock.

4.4

(1)

Warrant to Purchase Shares of Common Stock dated March 25, 2004 by Intrusion Inc. in favor of Black Point Partners, Inc.

4.5

(1)

Form of Lock-Up Agreement executed by Intrusion Inc. and each of its executive officers and directors.

4.6

(1)

Registration Rights Agreement dated as of March 25, 2004 by and among Intrusion Inc. and the persons and entities listed on Exhibit A thereto.

5.1

(3)

Opinion of Patton Boggs LLP, regarding the legality of the securities covered by this registration statement.

10.1

(1)

Securities Purchase Agreement dated as of March 25, 2004, by and among Intrusion Inc. and the purchasers listed on Exhibit A thereto.

23.1

 

Consent of KBA Group LLP.

23.2

 

Consent of Ernst & Young LLP.

23.3

(3)

Consent of Patton Boggs LLP (included in its opinion filed as Exhibit 5.1).

24.1

(2)

Power of Attorney.
Exhibit Number

Description
4.1(1)Form of Series 2 5% Convertible Preferred Stock Certificate.
4.2(1)Certificate of Designations of the Series 2 5% Convertible Preferred Stock of Intrusion Inc.
4.3(1)Form of Common Stock Purchase Warrant issued to the investors in the private placement.
4.4(1)Form of Representative's Warrant for the Purchase of Shares of Common Stock issued to certain affiliates of Stonegate Securities, Inc.
4.5(1)Form of Voting Agreement executed by each of the executive officers and directors of Intrusion Inc.
4.6(1)Registration Rights Agreement dated as of March 28, 2005 by and among Intrusion Inc. and each of the purchasers listed on the signature pages thereto.
5.1(2)Opinion of Patton Boggs LLP, regarding the legality of the securities covered by this registration statement.
10.1(1)Securities Purchase Agreement dated as of March 28, 2005, by and among Intrusion Inc. and the investors listed on the signature pages thereto.
10.2(1)Placement Agency Agreement dated February 7, 2005, by and between Intrusion Inc. and Stonegate Securities, Inc.
23.1Consent of KBA Group LLP.
23.2(2)Consent of Patton Boggs LLP (included in its opinion filed as Exhibit 5.1).
24.1(2)Power of Attorney.

(1)
Incorporated herein by reference to the Registrant's Current Report on Form 8-K dated March 25, 2004.29, 2005.

(2)
Previously filed with the Registrant's Registration Statement on Form S-3 filed on April 20, 2004.
(3)
Previously filed with the Registrant's Amendment No. 1 to Registration Statement filed on June 14, 2004.22, 2005.

II-4



SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Richardson, State of Texas, on July 23, 2004.May 19, 2005.

  INTRUSION INC.

 

 

By:

/s/
G. WARD PAXTON      Ward Paxton
G. Ward Paxton
President, Chief Executive Officer and Chairman of the Board

        Pursuant to the requirements of the Securities Act of 1933, as amended, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

Signature
 Title
 Date

/s/
G. WARD PAXTON      Ward Paxton
G. Ward Paxton

 

President, Chief Executive Officer and Chairman of the Board (principal executive officer)

 

July 23, 2004May 19, 2005


/s/
MICHAEL PAXTON      Michael Paxton
Michael Paxton


 


Vice President and Chief Financial Officer and General Counsel (principal financial and accounting officer)


 


July 23, 2004May 19, 2005


*

T. Joe Head


 


Vice President of Strategic Projects and Director


 


July 23, 2004May 19, 2005


*

J. Fred Bucy, Jr.


 


Director


 


July 23, 2004May 19, 2005


*

Donald M. Johnston


Director

 


Director




July 23, 2004May 19, 2005


*

James F. Gero


Director

 


Director




July 23, 2004May 19, 2005


/s/
MICHAEL PAXTON      Michael Paxton
Michael Paxton
*Attorney-in-FactAttorney-in-fact


 


Director


 


July 23, 2004May 19, 2005

II-5




QuickLinks

TABLE OF CONTENTS
INTRUSION INC.
RISK FACTORS
NOTE REGARDING FORWARD-LOOKING STATEMENTS
DESCRIPTION OF SECURITIES AND RELATED TRANSACTIONS
PLAN OF DISTRIBUTION
USE OF PROCEEDS
SELLING STOCKHOLDERS
LEGAL MATTERS
EXPERTS
WHERE YOU CAN FIND ADDITIONAL INFORMATION
PART II INFORMATION NOT REQUIRED IN PROSPECTUS
INDEX TO EXHIBITS
SIGNATURES