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                                                                   EXHIBIT 10.15


                           SECURITY EXCHANGE AGREEMENT

      Agreement entered into as of May 15, 2001, between Authentidate Holding
Corp. (f/k/a Bitwise Designs, Inc.), a Delaware corporation with its address at
2165 Technology Drive, Schenectady, New York, 12308 ("AHC"); Authentidate, Inc.,
a Delaware corporation with its address at Two World Financial Center, 43rd
Floor, New York, New York 10281 ("Authentidate"); and the undersigned holder of
securities of Authentidate whose name appears on the signature page annexed
hereto (the "Securityholder"). AHC, Authentidate and the Securityholders are
referred to collectively herein as the "Parties."

                                    RECITALS:

      WHEREAS, AHC owns approximately 82% of the outstanding shares of the
Common Stock of Authentidate; and

      WHEREAS, AHC has determined that it is in the best interests of its
shareholders that AHC make an offer to acquire the remaining outstanding shares
of Common Stock, options and warrants to purchase Common Stock of Authentidate
(the "Transaction") from the holders thereof; and

      WHEREAS, the Board of Directors of Authentidate has determined that it is
in the best interests of Authentidate and its shareholders that the Transaction
be conducted as proposed herein; and

      WHEREAS, the undersigned Securityholder of Authentidate has determined it
to be in his best interests to accept the Transaction upon the terms and
conditions contained herein.

      NOW, THEREFORE, in consideration of the premises and the mutual promises
herein made, and in consideration of the representations, warranties, and
covenants herein contained, and other good and valuable consideration, the
Parties agree as follows.

      1.    DEFINITIONS

      For purposes of this Agreement:

      "Authentidate Certificate" shall mean a certificate representing
Authentidate Shares or Authentidate Convertible Securities.

      "Authentidate Convertible Security" shall mean all options, warrants and
other securities issued by Authentidate which are convertible into Authentidate
Shares.

      "Authentidate Share" shall mean all shares of Common Stock of
Authentidate, par value $.001 per share, including any Authentidate Shares which
may be issued to any Authentidate Securityholder upon conversion of any
Authentidate Convertible Security.
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      "Authentidate Securities" means the Authentidate Shares and Authentidate
Convertible Securities.

      "Authentidate Securityholder" shall mean the beneficial owner of any
Authentidate Shares or Authentidate Convertible Securities.

      "AHC Shares" shall mean shares of Common Stock of AHC, par value $.001 per
share.

      "AHC Convertible Security" shall mean all options, warrants, and other
securities issued by AHC which are convertible into AHC Shares which may be
issued to Authentidate Securityholders in exchange for the Authentidate
Convertible Securities held by such Authentidate Securityholders.

      "Confidential Information" means any information which has been or is
concurrently herewith provided to an Authentidate Securityholder (i) in
connection with this Agreement, which is identified as, or should be reasonably
understood to be, confidential to Authentidate, and/or (ii) as a result of the
Authentidate Securityholder's investment in Authentidate or employment by
Authentidate (whether as an employee or consultant or otherwise), including, but
not limited to, trade secrets and confidential information disclosed to the
Securityholders or known by them as a consequence of their transactions with AHC
and/or Authentidate, whether or not pursuant to this Agreement, and not
generally known in the industry, concerning AHC's and Authentidate's business,
finances, methods, operations, know-how, trade secrets, data, technical
processes and formulas, source code, product designs, sales, cost and other
unpublished financial information, product and Business Plans, projections,
marketing data, information, research and development, customers, pricing and
information relating to proposed expansion and this Agreement and all exhibits
hereto.

      "Exchange Ratio" has the meaning set forth in Section 2(a) herein.

      "Liability" means any liability (whether known or unknown, whether
asserted or unasserted, whether absolute or contingent, whether accrued or
unaccrued, whether liquidated or unliquidated, and whether due or to become
due).

      "Person" means an individual, a partnership, a corporation, a limited
liability company or partnership, an association, a joint stock company, a
trust, a joint venture, an unincorporated organization, or a governmental entity
(or any department, agency, or political subdivision thereof).

      "Released Claims" means any and all claims, suits, damages, losses, causes
of action, known or unknown, of the undersigned Securityholder and any heir,
affiliate, officer, director, successor, agent or employee of Securityholder
that Securityholder may have in the future or presently has against AHC or
Authentidate (and/or their respective officers, directors, employees, affiliates
and agents) related to, arising under, or out of: (i) Securityholder's purchase
and/or ownership of Authentidate Securities or any documents related thereto or
evidencing same; (ii) the formation and operation of Authenticate from its
inception to the date hereof; (iii) any and all shareholder derivative actions
or any other shareholder claims arising out of or under the Delaware General


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Corporation Law and (iv) any agreement or contract (written or oral) for the
performance of services existing between the Authenticate Securityholder and
Authenticate other than a written employment agreement between Authenticate and
its employees.

      "Transfer" A Person shall be deemed to have effected a "Transfer" of a
security if such person directly or indirectly: (i) sells, pledges, encumbers,
grants an option with respect to, transfers or disposes of such security or any
interest in such security or (ii) enters into an agreement or commitment
providing for the sale of, pledge of, encumbrances of, grant of an option with
respect to, transfer of or disposition of such security or any interest therein.

      2.    OFFER TO EXCHANGE AUTHENTIDATE SECURITIES

      (a) Basic Transaction. Subject to the terms and conditions of this
Agreement, AHC hereby offers, until 5:00 pm on May 10, 2001, to purchase from
the undersigned Authentidate Securityholder any and all Authentidate Securities
owned by the undersigned in exchange for:

            (i)   with respect to the Authentidate Shares, such number of AHC
                  Shares on a basis of 1.5249 AHC Shares for each Authentidate
                  Share (the "Exchange Ratio") as set forth in clause 2(d)
                  hereof; and

            (ii)  with respect to the Authentidate Convertible Securities, such
                  number of AHC Convertible Securities as adjusted by the
                  Exchange Ratio, as set forth in Clause 2(e) below.

      All fractional AHC Shares or AHC Convertible Securities resulting from the
Transaction shall be rounded up or down to the nearest whole share.

      (b) The Closing. The closing of the Transaction contemplated by this
Agreement (the "Closing") shall be deemed to take place at the offices of AHC,
at 5:00 p.m. local time on May 10, 2001 (the "Closing Date").

      (c) Deliveries at the Closing. At or the prior to the Closing, (i) the
Securityholder will deliver to AHC the various certificates, instruments, and
documents as set forth below and (ii) AHC will deliver to the Securityholder the
various certificates, instruments, and documents as set forth below:

            (i)   On or before 5:00 pm on May 10, 2001, in order to accept this
                  offer, Securityholder shall deliver to AHC, an executed copy
                  of this Agreement and all original Authentidate Shares or
                  Authentidate Convertible Securities owned by Securityholder;
                  and


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            (ii)  Within 10 business days of receipt of the documents to be
                  delivered by the Securityholder in clause (i) above, AHC shall
                  deliver to the Securityholder the AHC Shares and/or AHC
                  Convertible Securities.

      IF YOU HAVE NEVER RECEIVED A PHYSICAL CERTIFICATE FOR YOUR AUTHENTIDATE,
      INC. SECURITIES, PLEASE CHECK THE BOX ON THE SIGNATURE PAGE.

      (d) Conversion of Authentidate Shares. Upon delivery of the
Securityholder's Authentidate Shares to AHC together with an executed copy of
this Agreement, subject to AHC's acceptance thereof, the Authentidate Shares
owned by Securityholder will be deemed converted automatically into the right to
receive that number of AHC Shares determined according to the Exchange Ratio.

      (e) Conversion of Authentidate Convertible Securities. Upon delivery of
the Securityholder's Authentidate Convertible Securities to AHC together with an
executed copy of this Agreement, the Authentidate Convertible Securities will be
converted automatically into the right to receive such number of AHC Convertible
Securities (and at such exercise or conversion price) as equals the number of
Authentidate Convertible Securities held by the Authentidate Securityholder
adjusted by the Exchange Ratio. The terms and conditions governing the holder's
right to receive AHC Shares pursuant to the AHC Convertible Securities shall be,
to the fullest extent possible, the same as governed such holder's right to
receive Authentidate Shares under the Authentidate Convertible Securities,
including the exercise term and registrations rights, if any, as are contained
in the Authentidate Convertible Securities. By way of example and not by
limitation, an Authentidate Convertible Security (such as a warrant) with an
exercise price of $3.00 per share for 100 shares with an exercise term of 3
years will be exchanged for a warrant to purchase 152 AHC Shares with an
exercise price of $1.97. The exercise term would remain at 3 years from the date
of original issuance. In the event that a holder of an option to purchase
Authentidate shares is not eligible under the AHC option plans to receive an AHC
option, then such person will receive an AHC warrant in replacement.

      (f) If any certificate for AHC Shares or AHC Convertible Securities is to
be issued in a name other than the name in which the Authentidate Securities
surrendered in exchange therefor is registered, it will be a condition of the
issuance thereof that (i) Authentidate Security so surrendered will be properly
endorsed and otherwise in proper form for transfer and accompanied by all other
documents required to evidence and effect such transfer and (ii) either (x) that
the Person requesting such exchange will have paid any transfer or other taxes
required by reason of the issuance of a certificate for AHC Shares or AHC
Convertible Securities in a name other than the name of the registered holder of
the Authentidate Security surrendered or (y) established to the satisfaction of
AHC, or any agent designated by AHC, that such tax has been paid or is not
applicable.


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      (g) Notwithstanding anything to the contrary in this Agreement, neither
AHC nor Authentidate shall be liable to an Authentidate Securityholder that was
properly delivered to a public official pursuant to any applicable abandoned
property, escheat or similar law.

      (h) AHC will be entitled to deduct and withhold from the consideration
otherwise payable pursuant to this Agreement to any holder of Authentidate
Shares or Authentidate Convertible Securities such amounts as AHC (or any
Affiliate thereof) shall determine in good faith they are required to deduct and
withhold with respect to the making of such payment under the Internal Revenue
Code, or any provision of federal, state, local or foreign tax law. To the
extent that amounts are so withheld by AHC, such withheld amounts will be
treated for all purposes of this Agreement as having been paid to the holder of
Authentidate Shares or Authentidate Convertible Securities in respect of whom
such deduction and withholding were made by AHC.

      (i) Additional Documents. Securityholder hereby covenants and agrees to
execute and deliver any additional documents necessary or desirable, in the
reasonable opinion of AHC, to carry out the intent of this Agreement.

      3.    RESTRICTED STATUS OF AHC SHARES AND AHC CONVERTIBLE SECURITIES

      (a) Securityholder understands that: (i) the AHC Shares and/or AHC
Convertible Securities have not been and are not being registered under the 1933
Act or any state securities laws, and may not be offered for sale, sold,
assigned or transferred unless (A) they have been subsequently registered
thereunder, or (B) Securityholder shall have delivered to the Company an opinion
of counsel acceptable to the Company, in a generally acceptable form, to the
effect that such AHC Shares and/or AHC Convertible Securities to be sold,
assigned or transferred may be sold, assigned or transferred pursuant to an
exemption from such registration.

      (b) Securityholder understands that the certificates or other instruments
representing the AHC Shares and/or AHC Convertible Securities shall bear a
restrictive legend in substantially the following form (and a stop-transfer
order may be placed against transfer of such stock certificates):

      THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED
      UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE
      SECURITIES LAWS. THE SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD,
      TRANSFERRED OR ASSIGNED (I) IN THE ABSENCE OF (A) AN EFFECTIVE
      REGISTRATION STATEMENT FOR THE SECURITIES UNDER THE SECURITIES ACT OF
      1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS, OR (B) AN OPINION
      OF COUNSEL, IN A GENERALLY ACCEPTABLE FORM, THAT REGISTRATION IS NOT
      REQUIRED UNDER SAID ACT OR APPLICABLE STATE SECURITIES LAWS OR (II) UNLESS
      SOLD PURSUANT TO RULE 144 UNDER SAID ACT.

      4.    NON-DISCLOSURE AND CONFIDENTIALITY.


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      The undesigned Authentidate Securityholder covenants and agrees, on behalf
of itself its affiliates, parent, subsidiaries, directors, officers, employees,
agents, heirs, successors and assigns, that it shall not, at any time during or
after the termination of this Agreement, make use of or disclose to any person,
corporation, or other entity, for any purpose whatsoever, any trade secret or
other Confidential Information and not to use any such Confidential Information
for any purpose other than the purpose for which it was originally disclosed to
the receiving party. The undersigned acknowledges that the Confidential
Information is the property of Authentidate and AHC. This Section 4 shall
survive termination of this Agreement.

      5.    SECURITYHOLDER RELEASE.

      Securityholder, on behalf of itself, its affiliates, parent, subsidiaries,
directors, officers, employees, agents, heirs, successors and assigns, hereby
releases and discharges in full all Released Claims, known and unknown, that he
may have existing as of the date hereof or in the future against AHC and/or
Authentidate and/or their respective affiliates, agents, officers, directors,
successors, assigns or employees. This Section 5 shall survive termination of
this Agreement. Securityholder's sole remedy and rights against AHC and
Authenticate after the date hereof shall be to enforce performance by AHC of
AHC's obligations under this Agreement.

      Before signing my name to this Agreement, the undersigned Securityholder
confirms and states that the undersigned:

      1.    has read it and understands that important rights are being given
            up.

      2.    means everything that is said; and

      3.    has signed it freely as the act and deed of the undersigned.


      6.    REPRESENTATIONS BY THE PARTIES.

      (a)   Representations of AHC

            (i) AHC has the full right, power, legal capacity and authority to
enter into this Agreement and to complete the transactions herein contemplated
and this Agreement constitutes a valid and binding obligation of AHC, and is
enforceable against AHC in accordance with its terms.

            (ii) The AHC Shares and AHC Convertible Securities to be issued to
the Authentidate Securityholders upon the consummation of the Transaction, when
delivered in accordance with this Agreement, shall be duly authorized, validly
issued, fully paid and nonassessable.


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             (iii) The issuance of such AHC Shares and AHC Convertible
Securities in connection with this Agreement will be exempt from registration
under the Securities Act of 1933, as amended, and applicable state securities
laws. The AHC Shares and AHC Convertible Securities to be issued to the
Authentidate Securityholders pursuant to Transaction are restricted securities
under Rule 144 of the Securities Act of 1933 and shall bear an appropriate
legend as such.

            (iv) AHC has delivered simultaneously herewith to the Authentidate
Securityholders a copy of the AHC (A) Proxy Statement dated as of February 16,
2001, as supplemented for its meeting of shareholders held on March 23, 2001,
(B) Annual Report for the fiscal year ended June 30, 2000 and (C) Reports on
Form 10Q for the quarters ended September 30, 2000 and December 31, 2000
(together such material being referred to as the "AHC Disclosure Documents"),
and such other material regarding the Transaction as may be necessary or
desirable to advise the Authentidate Securityholders of the terms and risks of
the Transaction

      (b)   Representations of Authentidate

            (i) Authentidate has the full right, power, legal capacity and
authority to enter into this Agreement and to complete the transactions herein
contemplated and this Agreement constitutes a valid and binding obligation of
Authentidate, and is enforceable against Authentidate in accordance with its
terms.

            (ii) All the issued and outstanding Authentidate Shares and
Authentidate Convertible Securities are validly issued, fully paid and
nonassessable.

            (iii) As of the date of this Agreement, Authentidate has an
authorized capitalization of 20,000,000 shares of Common Stock and 5,000,000
shares of Preferred Stock. As of the date of this Agreement, there are 3,602,436
shares of Common Stock of Authentidate issued and outstanding and no shares of
Preferred Stock of Authentidate issued and outstanding. Further, as of the date
of this Agreement, Authentidate has issued options and warrants to purchase
714,676 shares of its Common Stock.

      (c)   Representations of the Securityholder

      The Securityholder represents and warrants to AHC and Authentidate that
he:

            (i) is the beneficial owner of the Authentidate Shares and
Authentidate Convertible Securities indicated on the Securityholder signature
page of this Agreement, free and clear of any liens, claims, options, rights of
first refusal, co-sale rights, charges or other encumbrances;

            (ii) does not beneficially own any securities of Authentidate other
than the Authentidate Shares and Authentidate Convertible Securities indicated
on the Securityholder


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signature page of this Agreement;

            (iii) has the full power and authority to make, enter into and carry
out the terms of this Agreement and this Agreement constitutes a valid and
binding obligation of the Securityholder;

            (iv) acknowledges and understands: (a) that the issuance of such AHC
Shares and AHC Convertible Securities in connection with this Agreement will be
exempt from registration under the Securities Act of 1933, as amended, and
applicable state securities laws; and (b) that the AHC Shares and AHC
Convertible Securities to be issued to the Authentidate Securityholders pursuant
to Transaction are restricted securities under Rule 144 of the Securities Act of
1933 and shall bear an appropriate legend as such and (c) the AHC Shares and AHC
Convertible Securities are being acquired for his own account for investment and
not with a view to distribution, and with no present intention of distributing
the securities or selling the securities for distribution ;

            (v) Securityholder has received a copy, together with this
Agreement, of the (A) Proxy Statement dated as of February 16, 2001, as
supplemented for its meeting of shareholders held on March 23, 2001, (B) Annual
Report for the fiscal year ended June 30, 2000 (C) Reports on Form 10Q for the
quarters ended September 30, 2000 and December 31, 2000 (the Proxy Statement,
Annual Report and Forms 10Q together being referred to as the "AHC Disclosure
Documents") and (D) Disclosure Statement dated as of the dated hereof, and such
other material regarding the Transaction as may be necessary or desirable to
advise the Authentidate Securityholders of the terms and risks of the
Transaction.

            (vi) is an "accredited investor" as defined under Rule 501 of
Regulation D promulgated under the Securities Act of 1933, as amended.

            (vii) in the event that the Securityholder is a corporation or
similar entity, the person executing this Agreement on behalf of the
Securityholder has been duly authorized to so execute, and all corporate action
required to be taken to effectuate this Agreement has been completed.

            (viii) The Securityholder has such knowledge and experience in
financial and business matters as is required for evaluating the merits and
risks of making this investment, and the Securityholder has received such
information requested by the Securityholder concerning the business, management
and financial affairs of the Company in order to evaluate the merits and risks
of accepting or not accepting the Exchange Offer. Further, the Securityholder
acknowledges that the Securityholder has had the opportunity to ask questions
of, and receive answers from, the officers of the Company concerning the terms
and conditions of this investment and to obtain information relating to the
organization, operation and business of the Company and of the Company's
contracts, agreements and obligations. No representation or warranty is made by
the Company to induce the Securityholder to accept or reject the Exchange


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Offer, and any representation or warranty not made herein is specifically
disclaimed

      8.    TERMINATION

      (a) Termination of Agreement. AHC may terminate this Agreement at anytime
prior to May 15, 2001 without notice to the Securityholder.

      (b) Effect of Termination. If this Agreement is terminated pursuant to
Section 8(a) above, all rights and obligations of the Parties hereunder shall
terminate without any Liability of any Party to any other Party.

      9.    MISCELLANEOUS

      (a) Press Releases and Public Announcements. No Party shall issue any
press release or make any public announcement relating to the subject matter of
this Agreement prior to the Closing without the prior written approval of AHC
and Authentidate; provided, however, that any Party may make any public
disclosure it believes in good faith is required by applicable law or any
listing or trading agreement concerning its publicly-traded securities (in which
case the disclosing Party will use its reasonable best efforts to advise the
other Parties prior to making the disclosure). Notwithstanding the foregoing,
Authentidate and the Securityholders have received the AHC Disclosure Documents.

      (b) No Third-Party Beneficiaries. This Agreement shall not confer any
rights or remedies upon any Person other than the Parties and their respective
successors and permitted assigns.

      (c) Entire Agreement. This Agreement (including the documents referred to
herein) constitutes the entire agreement among the Parties and supersedes any
prior understandings, agreements, or representations by or among the Parties,
written or oral, to the extent they related in any way to the subject matter
hereof.

      (d) Succession and Assignment. This Agreement shall be binding upon and
inure to the benefit of the Parties named herein and their respective successors
and permitted assigns. No Party may assign either this Agreement or any of his
or its rights, interests, or obligations hereunder without the prior written
approval of AHC and Authentidate.

      (e) Counterparts. This Agreement may be executed in one or more
counterparts, each of which shall be deemed an original but all of which
together will constitute one and the same instrument.

      (f) Headings. The section headings contained in this Agreement are
inserted for convenience only and shall not affect in any way the meaning or
interpretation of this Agreement.


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      (g) Notices. All notices, requests, demands, claims, and other
communications hereunder will be in writing. Any notice, request, demand, claim,
or other communication hereunder shall be deemed duly given if (i) (and then
three business days after) it is sent by registered or certified mail, return
receipt requested, postage prepaid, or (ii) sent by overnight courier service,
and addressed to the intended recipient as set forth below:


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      If to AHC:                          If to Authentidate:

      Authentidate Holding Corp           Authentidate, Inc.
      2165 Technology Drive               Two World Financial Center, 43rd Floor
      Schenectady, NY 12308               New York, NY 10281
      Attn: John T. Botti                 Attn: Rob Van Naarden

      With a copy to:

      Goldstein & DiGioia LLP
      369 Lexington Avenue
      New York, New York 10017
      Attn: Victor DiGioia, Esq.

      If to the Securityholders:

      At the addresses provided on the Securityholder signature page of this
Agreement

Any Party may send any notice, request, demand, claim, or other communication
hereunder to the intended recipient at the address set forth above using any
other means (including personal delivery, expedited courier, messenger service,
fax or ordinary mail), but no such notice, request, demand, claim, or other
communication shall be deemed to have been duly given unless and until it
actually is received by the intended recipient. Any Party may change the address
to which notices, requests, demands, claims, and other communications hereunder
are to be delivered by giving the other Parties notice in the manner herein set
forth.

      (h) Governing Law. This Agreement shall be governed by and construed in
accordance with the domestic laws of the State of New York without giving effect
to any choice or conflict of law provision or rule (whether of the State of New
York or any other jurisdiction) that would cause the application of the laws of
any jurisdiction other than the State of New York. The Parties (a) agree that
any legal suit, action or proceeding arising out of or relating to this
Agreement shall be instituted exclusively in New York State Supreme Court,
County of New York, or in the United States District Court for the Southern
District of New York, (b) waives any objection which any Party may have now or
hereafter to the venue of any such suit, action or proceeding, and (c)
irrevocably consent to the jurisdiction of the New York State Supreme Court,
County of New York and the United States District Court for the Southern
District of New York in any such suit, action or procedure. Each of the Parties
further agrees to accept and acknowledge service of any and all process which
may be served in any suit, action or proceeding in the New York State Supreme
Court for the Southern District of New York, and agrees that service of process
mailed by certified mail to the recipients address as set forth on the signature
page hereto shall be deemed in every respect effective service of process in any
such suit, action or proceeding.


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      (i) Amendments and Waivers. No amendment of any provision of this
Agreement shall be valid unless the same shall be in writing and signed by the
Parties. No waiver by any Party of any default, misrepresentation, or breach of
warranty or covenant hereunder, whether intentional or not, shall be deemed to
extend to any prior or subsequent default, misrepresentation, or breach of
warranty or covenant hereunder or affect in any way any rights arising by virtue
of any prior or subsequent such occurrence.

      (j) Severability. Any term or provision of this Agreement that is invalid
or unenforceable in any situation in any jurisdiction shall not affect the
validity or enforceability of the remaining terms and provisions hereof or the
validity or enforceability of the offending term or provision in any other
situation or in any other jurisdiction.

      (k) Expenses. Each of the Parties will bear his or its own costs and
expenses (including legal fees and expenses) incurred in connection with this
Agreement and the transactions contemplated hereby.

      (l) Construction. Any reference to any federal, state, local, or foreign
statute or law shall be deemed also to refer to all rules and regulations
promulgated thereunder, unless the context requires otherwise. The word
"including" shall mean including without limitation. The Parties intend that
each representation, warranty, and covenant contained herein shall have
independent significance. If any Party has breached any representation,
warranty, or covenant contained herein in any respect, the fact that there
exists another representation, warranty, or covenant relating to the same
subject matter (regardless of the relative levels of specificity) which the
Party has not breached shall not detract from or mitigate the fact that the
Party is in breach of the first representation, warranty, or covenant.

      (m)   Incorporation of Exhibits, Annexes, and Schedules. The exhibits,
annexes, and schedules identified in this Agreement are incorporated herein
by reference and made a part hereof.

      (n) Specific Performance. Each of the Parties acknowledges and agrees that
the other Parties would be damaged irreparably in the event any of the
provisions of this Agreement are not performed in accordance with their specific
terms or otherwise are breached. Accordingly, the Parties agree that AHC and/or
Authentidate shall be entitled to an injunction or injunctions to prevent
breaches of the provisions of this Agreement and to enforce specifically this
Agreement and the terms and provisions hereof in any action instituted in any
court of the United States or any state thereof having jurisdiction over the
Parties and the matter, in addition to any other remedy to which they may be
entitled, at law or in equity.

      (o)   Documents Delivered.  Each Securityholder acknowledges receipt of
the AHC Disclosure Documents and the Disclosure Schedule.


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      IN WITNESS WHEREOF, the Parties hereto have executed this Agreement on the
date first above written.

AUTHENTIDATE HOLDING CORP.
(f/k/a BITWISE DESIGNS,  INC.)


By:____________________________
Name: John T. Botti
Title: Chief Executive Officer

AUTHENTIDATE, INC.


By:____________________________
Name: Rob Van Naarden
Title: Chief Executive Officer


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