<Page> EXHIBIT 4.1 <Table> <Caption> COMMON SHARES COMMON SHARES - ------------- ----------------- NUMBER SHARES ZQ DIGITALNET DIGITALNET HOLDINGS, INC. CUSIP 25389B 10 3 TRANSFERABLE IN THE CITIES OF INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE SEE REVERSE FOR DENVER, CO OR NEW YORK, NY CERTAIN DEFINITIONS -------------------------------------------------------------------------------------------------------- THIS CERTIFIES THAT IS THE OWNER OF -------------------------------------------------------------------------------------------------------- FULLY PAID AND NONASSESSABLE COMMON SHARES, $.001 PAR VALUE PER SHARE OF DIGITALNET HOLDINGS, INC. transferable on the books of the Company by the holder hereof in person or by a duly authorized attorney upon surrender of this Certificate properly endorsed. This Certificate is not valid until countersigned by the Transfer Agent and registered by the Registrar. WITNESS the facsimile seal of the Company and the facsimile signatures of its duly authorized officers. DATED: /s/ Jack Pearlstein /s/ Ken S. Bajaj SECRETARY AND TREASURER CHAIRMAN, PRESIDENT AND CHIEF EXECUTIVE OFFICER DIGITALNET HOLDINGS, INC. CORPORATE SEAL AUGUST 31, 2001 DELAWARE </Table> COUNTERSIGNED: COMPUTERSHARE TRUST COMPANY, INC. P.O. BOX 1596, DENVER, COLORADO 80201 By:___________________________________________________ Transfer Agent and Registrar - Authorized Signature <Page> DIGITALNET HOLDINGS, INC. The Company will furnish without charge to each stockholder who so requests from the Company's principal office a full statement of the powers, designations, preferences and relative participating, optional, or other special rights of each class of stock or series thereof and the qualifications, limitations or restrictions of such preferences and/or rights. The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations: <Table> <Caption> TEN COM - as tenants in common UNIF GIFT MIN ACT--___________________Custodian___________________ TEN ENT - as tenants by the entireties (Cust) (Minor) JT TEN - as joint tenants with right under Uniform Gifts to Minors of survivorship and not as Act________________________________________________ tenants in common (State) UNIF TRF MIN ACT-- _______________________Custodian (until age ___) (Cust) __________________________under Uniform Transfers (Minor) to Minors Act _____________________________________ (State) Additional abbreviations may also be used though not in the above list. For Value Received, _______________________________________ hereby sell(s), assign(s) and transfer(s) unto PLEASE INSERT SOCIAL SECURITY NUMBER OR OTHER IDENTIFYING NUMBER OF ASSIGNEE __________________________________________________ _____________________________________________________________________________________________________________________ (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE OF ASSIGNEE) _____________________________________________________________________________________________________________________ _______________________________________________________________________________________________________________Shares of the common shares represented by the within Certificate, and does hereby irrevocably constitute and appoint _____________________________________________________________________________________________________________Attorney to transfer the said shares on the books of the within named Company with full power of substitution in the premises. Dated ________________________ ________________________________________________________________________ NOTICE: THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT, OR ANY CHANGE WHATEVER. Signature(s) Guaranteed By _______________________________________________________________________________ THE SIGNATURE(S) MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM) PURSUANT TO S.E.C. RULE 17Ad-15. </Table>