SUPPLEMENTAL INDENTURE
TO THE INDENTURE
BY AND BETWEEN DIGITALNET, INC. AND
WELLS FARGO BANK, N.A.
(F/D/B/A WELLS FARGO BANK MINNESOTA, N.A.)(AS TRUSTEE)
DATED AS OF JULY 3, 2003

        This Supplemental Indenture (the “Supplemental Indenture”), dated as of
April 1, 2004, among User Technology Associates, Inc., a Virginia corporation
(the “Guaranteeing Subsidiary”), a subsidiary of DigitalNet, Inc. (or its
permitted successor), a Delaware corporation (the “Issuer”), and Wells Fargo
Bank Minnesota, National Association (or its permitted successor), as trustee
under the Indenture referred to below (the “Trustee”).

W I T N E S S E T H

        WHEREAS, the Issuer and the other Guarantors party thereto have
heretofore executed and delivered to the Trustee an indenture (the “Indenture”),
dated as of July 3, 2003, providing for the issuance of 9% Senior Notes due 2010
(the “Notes”);

        WHEREAS, the Indenture provides that under certain circumstances the
Guaranteeing Subsidiary shall execute and deliver to the Trustee a supplemental
indenture pursuant to which the Guaranteeing Subsidiary shall unconditionally
guarantee all of the Issuer’s obligations under the Notes and the Indenture on
the terms and conditions set forth herein (the “Note Guarantee”); and

        WHEREAS, pursuant to Section 9.01 of the Indenture, the Trustee is
authorized to execute and deliver this Supplemental Indenture.

        NOW THEREFORE, in consideration of the foregoing and for other good and
valuable consideration, the receipt of which is hereby acknowledged, the
Guaranteeing Subsidiary and the Trustee mutually covenant and agree for the
equal and ratable benefit of the Holders of the Notes as follows:

        1.       Capitalized Terms. Capitalized terms used herein without
definition shall have the meanings assigned to them in the Indenture.

        2.       Agreement to Guarantee.

        (a)        The Guaranteeing Subsidiary, along with all other Guarantors,
jointly and severally, and fully and unconditionally, guarantees to each Holder
of a Note authenticated and delivered by the Trustee and to the Trustee and its
successors and assigns, irrespective of the validity and enforceability of the
Indenture, the Notes or the obligations of the Issuer hereunder or thereunder,
that: (i) the principal of, premium, if any, and interest and Liquidated
Damages, if any, on the Notes will be promptly paid in full when due, whether at
maturity, by acceleration, redemption or otherwise, and interest on the overdue
principal of, premium, if any, and interest and Liquidated Damages, if any, on
the Notes, if lawful (subject in all cases to any applicable grace period
provided in the Indenture), and all other obligations of the Issuer to the
Holders or the Trustee hereunder or thereunder will be promptly paid in full or
performed, all in accordance with the terms hereof and thereof; (ii) in case of
any extension of time of payment or renewal of any Notes or any of such other
obligations, the same will be promptly paid in full when due or performed in
accordance with the terms of the extension or renewal, whether at stated
maturity, by acceleration or otherwise.  Failing payment when due of any amount
so guaranteed or any performance so guaranteed for whatever reason, the
Guarantors shall be jointly and severally obligated to pay the same immediately.
The Guaranteeing Subsidiary agrees that this is a guarantee of payment and not a
guarantee of collection.

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        (b)        The Guaranteeing Subsidiary hereby agrees that, to the
maximum extent permitted under applicable law, its obligations hereunder shall
be unconditional, irrespective of the validity, regularity or enforceability of
the Notes or the Indenture, the absence of any action to enforce the same, any
waiver or consent by any Holder of the Notes with respect to any provisions
hereof or thereof, the recovery of any judgment against the Issuer, any action
to enforce the same or any other circumstance that might otherwise constitute a
legal or equitable discharge or defense of a Guarantor. The Guaranteeing
Subsidiary, subject to Section 6.06 of the Indenture, hereby waives diligence,
presentment, demand of payment, filing of claims with a court in the event of
insolvency or bankruptcy of the Issuer, any right to require a proceeding first
against the Issuer, protest, notice and all demands whatsoever and covenants
that this Note Guarantee shall not be discharged except by complete performance
of the obligations contained in the Notes and the Indenture.

        (c)        The Guaranteeing Subsidiary agrees that if any Holder or the
Trustee is required by any court or otherwise to return to the Issuer, the
Guarantors, or any custodian, trustee, liquidator or other similar official
acting in relation to any of the Issuer or the Guarantors, any amount paid by
any of them to the Trustee or such Holder, this Note Guarantee, to the extent
theretofore discharged, shall be reinstated in full force and effect.

        (d)        The Guaranteeing Subsidiary agrees that the Guaranteeing
Subsidiary shall not be entitled to any right of subrogation in relation to the
Holders in respect of any obligations guaranteed hereby until payment in full of
all obligations guaranteed hereby. The Guaranteeing Subsidiary agrees that, as
between the Guarantors, on the one hand, and the Holders and the Trustee, on the
other hand, (x) the maturity of the obligations guaranteed hereby may be
accelerated as provided in Article Six of the Indenture for the purposes of this
Note Guarantee, notwithstanding any stay, injunction or other prohibition
preventing such acceleration in respect of the obligations guaranteed hereby,
and (y) in the event of any declaration of acceleration of such obligations as
provided in Article Six of the Indenture, such obligations (whether or not due
and payable) shall forthwith become due and payable by the Guarantors for the
purpose of this Note Guarantee. The Guaranteeing Subsidiary shall have the right
to seek contribution from any non-paying Guarantor so long as the exercise of
such right does not impair the rights of Holders under the Note Guarantee.

        3.       Limitation on Guarantor Liability. The Guaranteeing Subsidiary
confirms, pursuant to Section 10.02 of the Indenture, that it is the intention
of such Guaranteeing Subsidiary that its Note Guarantee not constitute a
fraudulent transfer or conveyance for purposes of Bankruptcy Law, the Uniform
Fraudulent Conveyance Act, the Uniform Fraudulent Transfer Act or any similar
federal or state law to the extent applicable to its Note Guarantee and, to
effectuate the foregoing intention, agrees hereby irrevocably that the
obligations of such Guaranteeing Subsidiary will be limited to the maximum
amount as will, after giving effect to all other contingent and fixed
liabilities of such Guaranteeing Subsidiary that are relevant under such laws,
and after giving effect to any collections from, rights to receive contribution
from or payments made by or on behalf of any other Guarantor in respect of the
obligations of such other Guarantor under Article Ten of the Indenture, result
in the obligations of such Guaranteeing Subsidiary under its Note Guarantee not
constituting a fraudulent transfer or conveyance.

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        4.       Execution and Delivery. The Guaranteeing Subsidiary agrees that
the Note Guarantees shall remain in full force and effect notwithstanding any
failure to endorse on each Note a notation of such Note Guarantee.

        5.       Guaranteeing Subsidiary May Consolidate, Etc., on Certain
Terms.

        The Guaranteeing Subsidiary may not sell or otherwise dispose of all or
substantially all of its assets to, or consolidate with or merge with or into
(whether or not such Guaranteeing Subsidiary is the surviving Person), another
Person, other than the Issuer or another Subsidiary Guarantor, unless:
immediately after giving effect to that transaction, no Default or Event of
Default exists; and either:

          (A)        the Person acquiring the property in any such sale or
disposition or the Person formed by or surviving any such consolidation or
merger is organized or existing under the laws of the United States, any state
thereof or the District of Columbia and assumes all the obligations of that
Guaranteeing Subsidiary under the Indenture, its Note Guarantee and the
Registration Rights Agreement pursuant to a supplemental indenture satisfactory
to the Trustee; or

          (B)        such sale or other disposition complies with Section 4.10
of the Indenture, including the application of the Net Proceeds therefrom.

          (C)        In case of any such consolidation, merger, sale or
conveyance governed by Section 10.04(a)(ii)(A) of the Indenture, upon the
assumption by the successor Person, by supplemental indenture, executed and
delivered to the Trustee and reasonably satisfactory in form to the Trustee, of
the Note Guarantee endorsed upon the Notes and the due and punctual performance
of all of the covenants and conditions of the Indenture to be performed by a
Guarantor, such successor Person shall succeed to and be substituted for a
Guarantor with the same effect as if it had been named herein as a Guarantor.
Such successor Person thereupon may cause to be signed any or all of the Note
Guarantees to be endorsed upon all of the Notes issuable hereunder which
theretofore shall not have been signed by the Issuer and delivered to the
Trustee. All the Note Guarantees so issued shall in all respects have the same
legal rank and benefit under the Indenture as the Note Guarantees theretofore
and thereafter issued in accordance with the terms of the Indenture as though
all of such Note Guarantees had been issued at the date of the execution
thereof.

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        6.       Release.

        Any Subsidiary Guarantor will be released and relieved of any
obligations under its Note Guarantee, (i) in connection with any sale or other
disposition of all or substantially all of the assets of that Subsidiary
Guarantor (including by way of merger or consolidation) to a Person that is not
(either before or after giving effect to such transaction) a Restricted
Subsidiary of the Issuer, if the sale or other disposition of all or
substantially all of the assets of that Subsidiary Guarantor complies with
Section 4.10 of the Indenture; (ii) in connection with any sale of all of the
Capital Stock of a Subsidiary Guarantor to a Person that is not (either before
or after giving effect to such transaction) a Restricted Subsidiary of the
Issuer, if the sale of all such Capital Stock of that Subsidiary Guarantor
complies with Section 4.10 of the Indenture; or (iii) if the Issuer designates
any Restricted Subsidiary that is a Subsidiary Guarantor as an Unrestricted
Subsidiary in accordance with the applicable provisions of the Indenture. Upon
delivery by the Issuer to the Trustee of an Officers’ Certificate and an Opinion
of Counsel to the effect that one of the foregoing requirements has been
satisfied and the conditions to the release of a Guarantor under this Section
10.05 of the Indenture have been met, the Trustee shall execute any documents
reasonably required in order to evidence the release of such Guarantor from its
obligations under its Note Guarantee.

        (b)        Any Guarantor not released from its obligations under its
Note Guarantee shall remain liable for the full amount of principal of and
interest and Liquidated Damages, if any, on the Notes and for the other
obligations of any Guarantor under the Indenture as provided in Article Ten of
the Indenture.

        7.       No Recourse Against Others. Pursuant to Section 12.07 of the
Indenture, no director, officer, employee, incorporator or stockholder of the
Guaranteeing Subsidiary shall have any liability for any obligations of such
Guaranteeing Subsidiary under the Notes, the Indenture, the Note Guarantees or
for any claim based on, in respect of, or by reason of, such obligations or
their creation.

        8.       NEW YORK LAW TO GOVERN. THE LAW OF THE STATE OF NEW YORK SHALL
GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE WITHOUT GIVING EFFECT
TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW.

        9.       Counterparts. The parties may sign any number of copies of this
Supplemental Indenture. Each signed copy shall be an original, but all of them
together represent the same agreement.

        10.       Effect of Headings. The Section headings herein are for
convenience only and shall not affect the construction hereof.

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        11.       Trustee. The Trustee shall not be responsible in any manner
whatsoever for or in respect of the validity or sufficiency of this Supplemental
Indenture or for or in respect of the recitals contained herein, all of which
recitals are made solely by the Guaranteeing Subsidiary and the Issuer.

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        IN WITNESS WHEREOF, the parties hereto have caused this Supplemental
Indenture to be duly executed and attested, all as of the date first above
written.

USER TECHNOLOGY ASSOCIATES, INC.

  By:  /s/ Ken S. Bajaj         Name: Ken S. Bajaj         Title: Chief
Executive Officer and President

  DIGITALNET, INC.

  By:  /s/ Ken S. Bajaj         Name: Ken S. Bajaj         Title: Chairman,
Chief Executive Officer               and President

  WELLS FARGO BANK , N.A.(F/D/B/A WELLS
FARGO BANK MINNESOTA, N.A.) as Trustee

  By:  /s/                                            Name:         Title:

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