PARENT SHAREHOLDERS INDEMNITY AGREEMENT


         THIS PARENT SHAREHOLDERS  INDEMNITY AGREEMENT  ("Agreement") is made as
of September 8, 1997, by and among CYLINK CORPORATION,  a California corporation
(the  "Purchaser") and the parties  identified on Schedule A hereto (the "Parent
Shareholders"), who collectively constitute all of the shareholders of A.R. DATA
SECURITY LTD., a limited liability company organized under the laws of the State
of Israel (the "Seller").

                                    RECITALS

A.  Contemporaneously  with the  execution and delivery of this  Agreement,  the
Purchaser  is  acquiring  from the Seller (i) all of the issued and  outstanding
shares of Algorithmic Research Ltd., a limited liability company organized under
the laws of the State of Israel (the  "Company"),  that are owned by the Seller,
and (ii) all of the issued and  outstanding  shares of Algart  Holdings  Ltd., a
limited  liability  company  organized  under the laws of the  State of  Israel,
pursuant to that certain Stock Purchase  Agreement dated as of September 7, 1997
among the Purchaser, the Company and the Seller (the "Purchase Agreement").

B. This  Agreement is being entered into pursuant to Section 7.7 of the Purchase
Agreement.

                                    AGREEMENT

         The parties hereto agree as follows:

1.       CERTAIN DEFINITIONS.

         Unless the  context  otherwise  requires,  the  capitalized  terms used
herein and not  otherwise  defined  herein  shall have the  respective  meanings
assigned  to  them  in the  Purchase  Agreement.  In  addition,  as used in this
Agreement, the following terms shall have the following respective meanings:

         A Parent  Shareholder's  "Percentage  Share" shall mean the "Percentage
Share" set forth opposite such Parent Shareholder's name on Schedule A hereto.

         An Individual Parent Shareholder's  "Specified  Intellectual  Property"
shall mean:  (i) those  material  patents  developed by such  Individual  Parent
Shareholder  that provide  intellectual  property  protection  for any software,
hardware or invention that (A) has been personally  developed by such Individual
Parent  Shareholder,  and (B) is material to the business of the Company and its
Subsidiaries;  and (ii) those material copyrights and trade secrets developed by
such Individual Parent Shareholder that provide intellectual property protection
for  any  software,  hardware  or  invention  that  (A)  relates  to  encryption
technology,  (B) has been personally  developed by such Individual  Shareholder,
and (C) is material to the  business  of the

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Company and its  Subsidiaries.  For  purposes  of the  preceding  sentence,  any
software,  hardware or invention  will be deemed to be "material to the business
of the  Company  and  its  Subsidiaries"  only  if such  software,  hardware  or
invention  is  incorporated  in, and is a material  component  of, any  Material
Company Product (or any material  component,  module,  feature or subassembly of
any such Material Company Product).

2.       REPRESENTATIONS AND WARRANTIES.

         2.1 Capitalization.  Each Parent Shareholder represents and warrants to
the Purchaser that, as of the time immediately  prior to the Closing,  except as
disclosed in the Company Schedule or as disclosed or otherwise  described in any
of the documents listed or otherwise  referred to in the Company  Schedule,  the
representations  and warranties of the Seller set forth in Sections 2.1, 2.5 and
2.6 of the Purchase Agreement were true and accurate in all material respects.

         2.2  Ownership  of Specified  Intellectual  Property.  Each  Individual
Parent Shareholder represents and warrants to the Purchaser that, as of the time
immediately prior to the Closing, except as disclosed in the Company Schedule or
as disclosed or otherwise  described in any of the documents listed or otherwise
referred to in the Company  Schedule,  such  Individual  Parent  Shareholder has
assigned to the Company (or has otherwise  permitted the Company to acquire) all
of his ownership rights (if any) in his Specified Intellectual Property, and has
not voluntarily  assigned (or otherwise  voluntarily granted or transferred) any
of his ownership rights (if any) in his Specified  Intellectual  Property to any
university or to any other third party.

         2.3 No  Implied  Representations.  Except  as  expressly  set  forth in
Sections 2.1 and 2.2 hereof, no Parent  Shareholder is making any representation
or warranty,  implied or otherwise, or is providing any assurances of any nature
whatsoever.  Without  limiting  the  generality  of  the  foregoing,  no  Parent
Shareholder  is making or shall be  deemed  to have made any  representation  or
warranty regarding the validity, ownership or status of any patent, copyright or
other intellectual  property right, or regarding the existence or absence of any
rights or any potential liabilities or risks associated with the exploitation of
any such intellectual property right.

3. SURVIVAL.  The  representations  and  warranties  contained in this Agreement
shall survive until the expiration of the applicable statute of limitations,  at
which time such  representations  and warranties  shall terminate and expire and
shall cease to be of any force or effect,  and all liability of the parties with
respect to such representations and warranties shall thereupon be extinguished.

4.       INDEMNIFICATION.

         4.1  Indemnification  by  the  Parent  Shareholders.   Subject  to  the
limitations on indemnification  set forth in Section 4.4 hereof and elsewhere in
this  Agreement,  each Parent  Shareholder  shall  indemnify  and  reimburse the
Purchaser for such Parent  Shareholder's

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Percentage Share of the net amount of any Damages incurred by the Purchaser as a
proximate  result of any inaccuracy in the  representation  and warranty made by
such Parent  Shareholder in Section 2.1 hereof.  For purposes of calculating the
net amount of such  Damages,  there  shall be  deducted  an amount  equal to the
aggregate  dollar  value  (determined  in the  manner  set  forth in the  Escrow
Agreement) of all cash and Escrow Shares  distributed by the Escrow Agent to the
Purchaser in connection  with any  indemnification  claim based on or related to
any  inaccuracy  or  alleged  inaccuracy  in  any  of  the  representations  and
warranties of the Seller  contained in Sections 2.1, 2.5 and 2.6 of the Purchase
Agreement.

         4.2 Indemnification by the Individual Parent  Shareholders.  Subject to
the limitations on indemnification set forth in Section 4.4 hereof and elsewhere
in this  Agreement,  each  Individual  Parent  Shareholder  shall  indemnify and
reimburse  the  Purchaser  for the net  amount of any  Damages  incurred  by the
Purchaser as a result of any inaccuracy in the  representation and warranty made
by such  Individual  Parent  Shareholder in Section 2.2 hereof.  For purposes of
calculating  the net amount of such  Damages,  there shall be deducted an amount
equal to the aggregate  dollar value  (determined in the manner set forth in the
Escrow Agreement) of all cash and Escrow Shares  distributed by the Escrow Agent
to the  Purchaser  in  connection  with any  indemnification  claim  based on or
related to any  inaccuracy or alleged  inaccuracy in any of the  representations
and  warranties  of the  Seller  contained  in Section  2.17(f) of the  Purchase
Agreement.

         4.3  Notification;  Control of Proceedings.  The Purchaser shall,  with
reasonable promptness,  give written notice (as provided in this Section 4.3) if
the Purchaser or any of its  affiliates  becomes  aware of any loss,  liability,
damage or expense with respect to which an indemnification claim may be asserted
by the Purchaser  under this  Agreement;  provided,  however,  that for the sole
purpose of determining  whether written notice must be provided by the Purchaser
under this  Section 4.3 (and for the purpose of  determining  whether any Parent
Shareholder  will  have  the  right  to  defend a  particular  action,  claim or
proceeding),  the  limitation  set forth in Section  4.4 shall not be taken into
account.  Such  written  notice  shall  be  given  to:  (i)  all of  the  Parent
Shareholders,  if such indemnification claim may be asserted pursuant to Section
4.1 hereof; or (ii) the particular Individual Parent Shareholder(s) against whom
such indemnification claim may be asserted, if such indemnification claim may be
asserted  pursuant to Section  4.2  hereof.  (The  failure of the  Purchaser  to
deliver such written notice with  reasonable  promptness  shall not be deemed to
bar or otherwise limit the rights of the Purchaser hereunder unless such failure
materially  prejudices  any of  the  rights  or  defenses  of any of the  Parent
Shareholders.)  If any claim is made by a third party or an action or proceeding
is commenced for which the Purchaser shall seek  indemnification from any Parent
Shareholder,  the Purchaser  shall,  with  reasonable  promptness,  give to such
Parent  Shareholder  written  notice of such  claim,  action or  proceeding  and
request  such Parent  Shareholder  to defend the same.  Such Parent  Shareholder
shall have the right to defend such claim,  action or  proceeding  at his or its
own expense, and (if such Parent Shareholder elects to defend such claim, action
or proceeding) shall give written notice to the Purchaser of the commencement of
the defense of such claim, action or proceeding by such Parent Shareholder.  The
Purchaser  shall be entitled to  participate at its own 

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expense with such Parent  Shareholder  in such defense  (subject to the right of
such Parent  Shareholder to control such defense),  but shall not be entitled in
any  way to  release,  waive,  settle,  modify  or pay  such  claim,  action  or
proceeding without the written consent of such Parent Shareholder.  In the event
that such Parent  Shareholder does not accept the defense of such claim,  action
or  proceeding  as  provided  above,  or does not  notify the  Purchaser  of its
election to defend such claim,  action or  proceeding  within 30 days after such
Parent  Shareholder's  receipt  of  written  notice  of such  claim,  action  or
proceeding from the Purchaser, the Purchaser shall have the full right to defend
such claim, action or proceeding in such manner as it may deem appropriate,  but
such  Parent  Shareholder  shall  not have any  liability  with  respect  to any
compromise  or settlement  effected  without its prior  written  consent  (which
consent shall not be unreasonably  withheld).  In the event a Parent Shareholder
shall assume the defense of any such claim, action or proceeding,  the Purchaser
shall  cooperate  in the defense of such claim,  action or  proceeding,  and the
records of each shall be available  to the other with  respect to such  defense;
provided, however, that such Parent Shareholder shall not, in the defense of any
such claim, action or proceeding,  consent to the entry of any judgment or enter
into any settlement  where such entry of judgment or settlement does not include
a provision  releasing  the Purchaser  from all  liability  with respect to such
claim,  action or proceeding,  except with the written  consent of the Purchaser
(which consent shall not be unreasonably withheld).

         4.4 Limitations on Indemnification.  Notwithstanding anything contained
in  Section  4.1 or 4.2 hereof or  elsewhere  in this  Agreement:  (a) no Parent
Shareholder  shall be liable to the Purchaser under this Agreement except to the
extent that the cumulative amount of indemnifiable  Damages actually incurred by
the Purchaser as a proximate result of all  inaccuracies in the  representations
and  warranties  made by such  Parent  Shareholder  in this  Agreement  actually
exceeds the Unused  Deductible  Amount;  and a Parent  Shareholder shall only be
required  to pay,  and  shall  only be  liable  for,  the  amount  by which  the
cumulative amount of indemnifiable Damages actually incurred by the Purchaser as
a  proximate  result  of  all  such  inaccuracies  in  the  representations  and
warranties made by such Parent  Shareholder in this Agreement  actually  exceeds
the Unused  Deductible  Amount;  and (b) no Parent  Shareholder  shall be liable
under this  Agreement  with  respect to any  indemnification  claim  based on an
inaccuracy in any  representation or warranty of such Parent  Shareholder if any
of the Purchaser's  officers or directors had actual knowledge of the inaccuracy
in  such   representation   or  warranty  (or  of  any  facts  or  circumstances
constituting  or resulting in such  inaccuracy)  prior to the  execution of this
Agreement;  provided, however, that the limitation provided by this clause "(b)"
shall not be available to a Parent  Shareholder if such Parent  Shareholder also
had such actual knowledge of the inaccuracy in such  representation and warranty
(or of such facts or circumstances constituting or resulting in such inaccuracy)
prior to the execution of the Purchase  Agreement.  For purposes of this Section
4.4,  "Unused  Deductible  Amount"  shall mean the  $250,000  deductible  amount
referred  to in  Section  5.5 of the  Purchase  Agreement,  to the  extent  such
deductible  amount has not been utilized under the Purchase  Agreement to reduce
the  amount of  indemnification  payments  made to the  Purchaser  by the Escrow
Agent.

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         4.5 Exclusive  Remedy.  Without  limitation of any term of Article V of
the Purchase Agreement or the Escrow Agreement relating to the Purchaser's right
to make  indemnification  claims  against the cash and Escrow Shares held by the
Escrow Agent, the indemnification  provided for in Section 4 hereof shall be the
exclusive  right and remedy of the  Purchaser  with respect to any claim against
any Parent  Shareholder in connection with any of the transactions  contemplated
by or referred to in the  Purchase  Agreement.  No claim or cause of action with
respect to any inaccuracy in any  representation  or warranty  contained in this
Agreement shall be enforceable unless made in accordance with the procedures set
forth in Section 4 hereof. Without limiting the generality of the foregoing (and
without limiting the Purchaser's right under Article V of the Purchase Agreement
to make  indemnification  claims  against the cash and Escrow Shares held by the
Escrow  Agent),  except as  expressly  provided in this  Agreement,  none of the
Parent  Shareholders  shall have any liability to the Purchaser or to any of the
Purchaser's  affiliates  for any  breach by the  Seller  of any of the  Seller's
covenants,  representations or warranties contained in the Purchase Agreement or
for any  breach  by any  Parent  Shareholder  of any of the  representations  or
warranties contained in this Agreement.

         4.6 Subrogation.  To the extent that any Parent Shareholder makes or is
required to make any indemnification  payment to the Purchaser:  (a) such Parent
Shareholder  shall be  entitled to  exercise,  and shall be  subrogated  to, any
rights and remedies  (including rights of indemnity,  rights of contribution and
other  rights  of  recovery)  that  the  Purchaser  or any  of  the  Purchaser's
affiliates  may have  against  any other  person or entity  with  respect to any
Damages,  circumstances  or  matter to which  such  indemnification  payment  is
directly or  indirectly  related;  (b) the  Purchaser  shall  permit such Parent
Shareholder  to use the name of the Purchaser and each of its  affiliates in any
transaction or in any proceeding or other matter involving any of such rights or
remedies;  and (c)  the  Purchaser  shall  take,  and  shall  cause  each of its
affiliates  to take,  such  actions as such Parent  Shareholder  may  reasonably
request  for the  purpose of  enabling  such  Parent  Shareholder  to perfect or
exercise such Parent Shareholder's right of subrogation hereunder. Any rights of
a Parent  Shareholder to  subrogation  pursuant to this Section 4.6 shall not be
exercisable until such Parent  Shareholder shall have fully performed his or its
obligations  pursuant  to  this  Agreement  as to  the  indemnification  of  the
Purchaser  (with  respect to the  particular  indemnification  claim  involved);
provided,  however,  that prior to the full performance of such  indemnification
obligations  (and to the extent  reasonably  required to preserve  the rights of
such  Parent  Shareholder  to  subrogation),  such Parent  Shareholder  shall be
permitted to take any action so required to preserve such subrogation rights.

         4.7 Acts of Fraud. Each Parent Shareholder acknowledges and agrees that
no limitation or other term contained in this Agreement,  the Purchase Agreement
or the  Escrow  Agreement  shall  serve  to  limit  any  liability  such  Parent
Shareholder may otherwise have under applicable law for any fraud  intentionally
committed  upon the  Purchaser  by such Parent  Shareholder  with respect to any
representation  made  to  the  Purchaser  in  any  written  agreement  with  the
Purchaser.

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         4.8 No  Limitation  of  Actions.  Nothing  contained  herein  or in the
Purchase  Agreement or the Escrow Agreement shall require the Purchaser to first
pursue its rights or remedies under Article V of the Purchase  Agreement and the
Escrow Agreement as to any claim by the Purchaser that is based on the breach of
any  representation  or  warranty  in  both  this  Agreement  and  the  Purchase
Agreement. To the extent that the Purchaser shall first recover Damages from one
or more Parent  Shareholders  pursuant to this  Agreement  prior to any recovery
pursuant to Article V of the Purchase Agreement, the amounts recovered from such
Parent  Shareholder  shall be deducted from amounts payable  pursuant to Section
5.2 of the Purchase Agreement.


5.  GOVERNING LAW. This  Agreement and the legal  relations  between the parties
arising  hereunder  shall be governed by and  interpreted in accordance with the
laws  of  the  State  of  California  without  regard  to  its  conflict  of law
provisions, and shall inure to the benefit of and be binding upon the successors
and assigns of the  parties  hereto.  Any dispute  arising out of or relating to
this Agreement shall be resolved through binding  arbitration under the Rules of
Conciliation and Arbitration of the International Chamber of Commerce. The venue
for such arbitration proceedings shall be London, England. The arbitrator's fees
and other related  expenses of any  arbitration  under this  Agreement  (such as
expenses for transcripts of the arbitration  proceedings)  shall be borne by the
Purchaser and the Parent  Shareholders  who are parties to such  arbitration  in
such  proportions  as shall be determined by the  arbitrator,  or if there is no
such determination, then such fees and other expenses shall be borne one-half by
the Purchaser and one-half divided equally among the Parent Shareholders who are
parties to such arbitration. The resolution of a dispute by the arbitrator shall
be  conclusive  and binding upon the parties  hereto and judgment may be entered
thereon in any court having jurisdiction  thereof. The arbitrator shall have the
authority to make an award of actual compensatory damages incurred by a party in
connection with a dispute, but shall have no right to grant special, punitive or
exemplary  damages or indirect or consequential  damages or to grant any form of
equitable relief.

6. COUNTERPARTS. This Agreement may be executed in one or more counterparts, all
of which shall be considered one and the same document.

7. NOTICES.  Any notice required or permitted  hereunder shall be in writing and
shall be deemed given (a) when  delivered  in person,  (b) three  business  days
after  delivery to an  "overnight"  courier,  or (c) 24 hours after  delivery by
facsimile  transmission  (if  receipt  of  such  facsimile  is  evidenced  by  a
transmission  report or other reasonable evidence of the successful and accurate
transmission of such notice), in each case addressed as follows:

         If to the Purchaser:               Cylink Corporation
                                            910 Hermosa Court
                                            Sunnyvale, CA  94086
                                            Attn:  Robert B. Fougner
                                            Fax:  408-774-4952

                                       6



         With a copy to:                    Morrison & Foerster LLP
                                            755 Page Mill Road
                                            Palo Alto, CA  94304
                                            Attn:  Michael C. Phillips
                                            Fax:  650-494-0792

         If to a Parent
         Shareholder:                       At the address for such Parent 
                                            Shareholder as set forth in
                                            Schedule A hereto


         With a copy to:                    Shinar, Shachor, Weissberger
                                            5 Belt Hillel Street, 3rd Floor
                                            Tel Aviv 67017, Israel
                                            Attn:  Doron Shinar
                                            Fax:  972-3-562-1905

         Addresses  may be changed  by written  notice  given  pursuant  to this
Section.  Any notice given  hereunder may be given on behalf of any party by his
or its counsel or other authorized representative.

8. ENTIRE AGREEMENT.  This Agreement  constitutes the full and entire understand
among the parties  regarding  the matters set forth  herein and  supersedes  all
prior agreements and understandings, both written and oral, among or between any
of the parties with respect to the subject matter hereof.

9.  AMENDMENTS.  This  Agreement may not be amended,  modified or  supplemented,
except by means of a written amendment signed by all parties hereto.

10.  LIQUIDATION  OF  SELLER.  Following  the  liquidation  of  the  Seller,  in
exercising the Seller's  contractual  rights under the Purchase  Agreement,  the
Parent  Shareholders  will  be  subject  to  the  limitations  and  restrictions
applicable  to the exercise of such  contractual  rights under Article V and the
other  provisions  of  the  Purchase  Agreement.  In  addition,   following  the
liquidation of the Seller,  the respective Parent  Shareholders will cause to be
performed all  continuing  contractual  obligations of the Seller under Sections
1.2(b),  4.7,  4.13,  9.1,  11.3,  11.6 and 11.7 of the Purchase  Agreement  and
Section 4(e) of the Escrow Agreement;  provided,  however, that, in the event of
any failure to cause any of such obligations to be performed,  the liability (if
any) of each Parent  Shareholder  shall be limited to such Parent  Shareholder's
Percentage  Share of the  compensable  damages  incurred by the  Purchaser  as a
proximate  result of such  failure.  Notwithstanding  anything  to the  contrary
contained in this Agreement or in any other  document (and without  limiting the
effect of the proviso to the preceding  sentence),  the total cumulative maximum
liability of each Parent  Shareholder for all breaches of this Agreement and all
breaches of the Seller's Agreement of even date herewith shall be limited in the
aggregate

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to the net dollar value of the assets of the Seller  distributed  to such Parent
Shareholder by the Seller in the dissolution and liquidation of the Seller,  and
such Parent Shareholder's  aggregate liability hereunder and thereunder shall in
no event exceed such amount.

11. MISCELLANEOUS. For purposes of this Agreement, the masculine gender shall be
deemed to include the feminine and neuter  genders,  and the neuter gender shall
be deemed to include the masculine and feminine genders.



                                       8




         IN WITNESS WHEREOF,  the parties hereto have executed this Agreement as
of the date first stated above.

CYLINK CORPORATION


By:  /s/ John V. Kalb, Jr.
   -------------------------------------------
         John V. Kalb, Jr.
         Vice President,
         Strategy and Business Development

By:  /s/ Yossi Tulpan
   -------------------------------------------
         Yossi Tulpan


By:  /s/ Amos Fiat
   -------------------------------------------
         Amos Fiat

By:  /s/ Yossi Cohen
   -------------------------------------------
         Yossi Cohen


KOOR CAPITAL MARKETS


By:  /s/ Itzak Chalamish
   -------------------------------------------
         Itzak Chalamish
         President

By:  /s/ Yair Na'aman
   -------------------------------------------
         Yair Na'aman
         Head of Finance Division

TELRAD HOLDINGS LTD.


By:  /s/ Oded Koritshoner 
   -------------------------------------------
         Oded Koritshoner
         Managing Director


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By:   /s/
   -------------------------------------------



                                       10



                                   SCHEDULE A

                   TO PARENT SHAREHOLDERS INDEMNITY AGREEMENT


Name and Address of Parent Shareholder                    Percentage Share

Yossi Tulpan                                                       31.407%
21 Bilu Street, Ness Tziona, Israel

Amos Fiat                                                          31.407%
20 Shalom Ash Street, Tel Aviv, Israel

Yossi Cohen                                                        10.337%
19 Mordechai Kaplan Street, Holon, Israel

Koor Capital Markets                                                7.501%
19 Rothschild Boulevard, Tel Aviv, Israel

Telrad Holdings Ltd.                                               19.348%
19 Rothschild Boulevard, Tel Aviv, Israel


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