Registration Rights Agreement

Registration Rights Agreement

                                                                    EXHIBIT 10.2

                          REGISTRATION RIGHTS AGREEMENT

      This Registration Rights Agreement (this "Agreement") is made and entered
into as of October 22, 2002, among Authentidate Holding Corp., a Delaware
corporation (the "Company"), and the purchasers signatory hereto (each such
purchaser is a "Purchaser" and all such purchasers are, collectively, the
"Purchasers").

      This Agreement is made pursuant to the Securities Purchase Agreement,
dated as of the date hereof among the Company and the Purchasers (the "Purchase
Agreement").

      The Company and the Purchasers hereby agree as follows:

   1. Definitions

      CAPITALIZED TERMS USED AND NOT OTHERWISE DEFINED HEREIN THAT ARE DEFINED
IN THE PURCHASE AGREEMENT SHALL HAVE THE MEANINGS GIVEN SUCH TERMS IN THE
PURCHASE AGREEMENT. As used in this Agreement, the following terms shall have
the following meanings:

            "Business Day" means any day except Saturday, Sunday and any day
      which shall be a legal holiday or a day on which banking institutions in
      the State of New York or the State of California are authorized or
      required by law or other government actions to close.

            "Effectiveness Date" means, with respect to the initial Registration
      Statement required to be filed hereunder, the earlier of (i) the 60th day
      following the Closing Date (120th day in the event of a "full review" by
      the Commission) and (ii) the fifth day following the date on which the
      Company is notified by the Commission that such Registration Statement
      will not be reviewed or is no longer subject to further review and
      comments.

            "Effectiveness Period" shall have the meaning set forth in Section
      2(a).

            "Filing Date" means, with respect to the initial Registration
      Statement required to be filed hereunder, the 30th day following the
      Closing Date.

            "Holder" or "Holders" means the holder or holders, as the case may
      be, from time to time of Registrable Securities.

            "Indemnified Party" shall have the meaning set forth in Section
      5(c).

            "Indemnifying Party" shall have the meaning set forth in Section
      5(c).



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            "Prospectus" means the prospectus included in a Registration
      Statement (including, without limitation, a prospectus that includes any
      information previously omitted from a prospectus filed as part of an
      effective registration statement in reliance upon Rule 430A promulgated
      under the Securities Act), as amended or supplemented by any prospectus
      supplement, with respect to the terms of the offering of any portion of
      the Registrable Securities covered by a Registration Statement, and all
      other amendments and supplements to the Prospectus, including
      post-effective amendments, and all material incorporated by reference or
      deemed to be incorporated by reference in such Prospectus.

            "Registrable Securities" means all of the shares of Common Stock
      issuable upon conversion in full of the Debentures, exercise in full of
      the Warrants, shares issuable in lieu of the payment of liquidated
      damages, together with any securities issued or issuable in lieu of
      interest or upon any stock split, dividend or other distribution
      recapitalization or similar event with respect to the foregoing or
      pursuant to any anti-dilution provisions contained in the Debentures or
      the Warrants.

            "Registration Statement" means the registration statements required
      to be filed hereunder and any additional registration statements
      contemplated by Section 3(c), including (in each case) the Prospectus,
      amendments and supplements to such registration statement or Prospectus,
      including pre- and post-effective amendments, all exhibits thereto, and
      all material incorporated by reference or deemed to be incorporated by
      reference in such registration statement.

            "Rule 415" means Rule 415 promulgated by the Commission pursuant to
      the Securities Act, as such Rule may be amended from time to time, or any
      similar rule or regulation hereafter adopted by the Commission having
      substantially the same effect as such Rule.

            "Rule 424" means Rule 424 promulgated by the Commission pursuant to
      the Securities Act, as such Rule may be amended from time to time, or any
      similar rule or regulation hereafter adopted by the Commission having
      substantially the same effect as such Rule.

            "Special Counsel" means one special counsel to the Holders, for
      which the Holders will be reimbursed by the Company pursuant to Section 4.

            "Warrants" shall mean the Common Stock purchase warrants issued to
      the Purchasers pursuant to the Purchase Agreement.

   2. Shelf Registration



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      (a) On or prior to each Filing Date, the Company shall prepare and file
with the Commission a "Shelf" Registration Statement covering the resale of all
Registrable Securities applicable to such Filing Date for an offering to be made
on a continuous basis pursuant to Rule 415. The Registration Statement shall be
on Form S-3 and shall contain (except if otherwise directed by the Holders)
substantially the "Plan of Distribution" attached hereto as Annex A. The Company
shall use its best efforts to cause the Registration Statement to be declared
effective under the Securities Act as promptly as possible after the filing
thereof, but in any event prior to the applicable Effectiveness Date, and shall
use its best efforts to keep such Registration Statement continuously effective
under the Securities Act until the date which is two years after the date that
such Registration Statement is declared effective by the Commission or such
earlier date when all Registrable Securities covered by such Registration
Statement have been sold or may be sold without volume restrictions pursuant to
Rule 144(k) as determined by the counsel to the Company pursuant to a written
opinion letter to such effect, addressed and acceptable to the Company's
transfer agent and the affected Holders (the "Effectiveness Period").

      (b) The Registration Statements to be filed hereunder shall include 100%
of the Registrable Securities.

      (c) If: (i) a Registration Statement is not filed on or prior to its
Filing Date (if the Company files a Registration Statement without affording the
Holder the opportunity to review and comment on the same as required by Section
3(a), the Company shall not be deemed to have satisfied clause (i)), or (ii) the
Company fails to file with the Commission a request for acceleration in
accordance with Rule 461 promulgated under the Securities Act, within five
Trading Days of the date that the Company is notified (orally or in writing,
whichever is earlier) by the Commission that a Registration Statement will not
be "reviewed," or not subject to further review, or (iii) prior to its Effective
Date, the Company fails to file a pre-effective amendment and otherwise respond
in writing to comments made by the Commission in respect of such Registration
Statement within 20 Trading Days after the receipt of comments by or notice from
the Commission that such amendment is required in order for a Registration
Statement to be declared effective, or (iv) a Registration Statement filed or
required to be filed hereunder is not declared effective by the Commission by
its Effectiveness Date, or (v) after the Effective Date, a Registration
Statement ceases for any reason to remain continuously effective as to all
Registrable Securities for which it is required to be effective, or the Holders
are not permitted to utilize the Prospectus therein to resell such Registrable
Securities for 5 consecutive Trading Days or in any individual case an aggregate
of 10 Trading Days during any 12 month period (which need not be consecutive
Trading Days) (any such failure or breach being referred to as an "Event", and
for purposes of clause (i) or (iv) the date on which such Event occurs, or for
purposes of clause (ii) the date on which such five Trading Day period is
exceeded, or for purposes of clause (iii) the date which such 20 Trading Day
period is exceeded, or for purposes of clause (v) the date on which such 5 or 10
Trading Day period, as applicable, is exceeded being referred to as "Event
Date"), then, on each such Event Date and every monthly anniversary thereof
until the applicable Event is cured, the Company shall pay to each Holder an
amount in


                                       3

cash, as liquidated damages and not as a penalty, equal to 2.0% of (i) the
purchase price paid by such Holder pursuant to the Purchase Agreement, and (ii)
if the Warrants are "in the money", the value of any outstanding Warrants
(valued at the difference between the average VWAP during the applicable month
and the Exercise Price multiplied by the number of shares of Common Stock the
Warrants are exercisable into) for the first month following such Event Date and
2.0% per month thereafter; provided, however, that in the event that the Company
is negotiating a merger, consolidation, acquisition or sale of all or
substantially all of its assets or a similar transaction and in the written
opinion of counsel to the Company, the underlying Shares Registration Statement
would be required to be amended to include information concerning such
transactions or the parties thereto that is not available or may not be publicly
disclosed at the time, the Company shall be permitted an additional 10
non-consecutive Trading Days under clause (vi) above during any 12 month period
relating to such an event; provided, further, the Company must give the Holders
notice in writing promptly upon knowledge that such an Event will occur (without
indicating the nature of such Event) and such notice must be acknowledged in
writing by each Holder. If the Company fails to pay any liquidated damages
pursuant to this Section in full within seven days after the date payable, the
Company will pay interest thereon at a rate of 18% per annum (or such lesser
maximum amount that is permitted to be paid by applicable law) to the Holder,
accruing daily from the date such liquidated damages are due until such amounts,
plus all such interest thereon, are paid in full and at the option of the
Holder, such liquidated damages be paid in shares of Common Stock under the
Warrant. The liquidated damages pursuant to the terms hereof shall apply on a
pro-rata basis for any portion of a month prior to the cure of an Event.

   3. Registration Procedures

      In connection with the Company's registration obligations hereunder, the
Company shall:

      (a) Not less than five Business Days prior to the filing of each
Registration Statement or any related Prospectus or any amendment or supplement
thereto (including any document that would be incorporated or deemed to be
incorporated therein by reference), the Company shall, (i) furnish to the
Holders and their Special Counsel copies of all such documents proposed to be
filed, which documents (other than those incorporated or deemed to be
incorporated by reference) will be subject to the review of such Holders and
their Special Counsel, and (ii) cause its officers and directors, counsel and
independent certified public accountants to respond to such inquiries as shall
be necessary, in the reasonable opinion of respective counsel to conduct a
reasonable investigation within the meaning of the Securities Act. The Company
shall not file the Registration Statement or any such Prospectus or any
amendments or supplements thereto to which the Holders of a majority of the
Registrable Securities and their Special Counsel shall reasonably object,
provided, the Company is notified of such objection no later than 5 Business
Days after the Holders have been so furnished copies of such documents.



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      (b) (i) Prepare and file with the Commission such amendments, including
post-effective amendments, to a Registration Statement and the Prospectus used
in connection therewith as may be necessary to keep a Registration Statement
continuously effective as to the applicable Registrable Securities for the
Effectiveness Period and prepare and file with the Commission such additional
Registration Statements in order to register for resale under the Securities Act
all of the Registrable Securities; (ii) cause the related Prospectus to be
amended or supplemented by any required Prospectus supplement, and as so
supplemented or amended to be filed pursuant to Rule 424; (iii) respond as
promptly as reasonably possible, and in any event within 15 days, to any
comments received from the Commission with respect to a Registration Statement
or any amendment thereto and as promptly as reasonably possible provide the
Holders true and complete copies of all correspondence from and to the
Commission relating to a Registration Statement; and (iv) comply in all material
respects with the provisions of the Securities Act and the Exchange Act with
respect to the disposition of all Registrable Securities covered by a
Registration Statement during the applicable period in accordance with the
intended methods of disposition by the Holders thereof set forth in such
Registration Statement as so amended or in such Prospectus as so supplemented.

      (c) If the number of Registrable Securities issuable at any time exceeds
85% of the number of shares of Common Stock then registered in a Registration
Statement, then the Company shall file an additional Registration Statement
covering the resale of by the Holders of not less than 100% of the number of
Registrable Securities required in order that all Underlying Shares and all
Warrant Shares issuable upon exercise of the Warrants would then be registered
in accordance with this Agreement.

      (d) Notify the Holders of Registrable Securities to be sold and their
Special Counsel as promptly as reasonably possible (and, in the case of (i)(A)
below, not less than five Business Days prior to such filing) and (if requested
by any such Person) confirm such notice in writing no later than one Business
Day following the day (i)(A) when a Prospectus or any Prospectus supplement or
post-effective amendment to a Registration Statement is proposed to be filed;
(B) when the Commission notifies the Company whether there will be a "review" of
such Registration Statement and whenever the Commission comments in writing on
such Registration Statement (the Company shall provide true and complete copies
thereof and all written responses thereto to each of the Holders); and (C) with
respect to a Registration Statement or any post-effective amendment, when the
same has become effective; (ii) of any request by the Commission or any other
Federal or state governmental authority for amendments or supplements to a
Registration Statement or Prospectus or for additional information; (iii) of the
issuance by the Commission of any stop order suspending the effectiveness of a
Registration Statement covering any or all of the Registrable Securities or the
initiation of any Proceedings for that purpose; (iv) if at any time any of the
representations and warranties of the Company contained in any agreement
contemplated hereby ceases to be true and correct in all material respects; (v)
of the receipt by the Company of any notification with respect to the suspension
of the qualification or exemption from qualification of any of the Registrable
Securities for sale in any jurisdiction, or the initiation or threatening of any
Proceeding for such purpose; and (vi) of the occurrence of any event or passage
of


                                       5

time that makes the financial statements included in a Registration Statement
ineligible for inclusion therein or any statement made in a Registration
Statement or Prospectus or any document incorporated or deemed to be
incorporated therein by reference untrue in any material respect or that
requires any revisions to a Registration Statement, Prospectus or other
documents so that, in the case of a Registration Statement or the Prospectus, as
the case may be, it will not contain any untrue statement of a material fact or
omit to state any material fact required to be stated therein or necessary to
make the statements therein, in light of the circumstances under which they were
made, not misleading.

      (e) Promptly deliver to each Holder and their Special Counsel, without
charge, as many copies of the Prospectus or Prospectuses (including each form of
prospectus) and each amendment or supplement thereto as such Persons may
reasonably request. The Company hereby consents to the use of such Prospectus
and each amendment or supplement thereto by each of the selling Holders in
connection with the offering and sale of the Registrable Securities covered by
such Prospectus and any amendment or supplement thereto.

      (f) Prior to any public offering of Registrable Securities, use its best
efforts to register or qualify or cooperate with the selling Holders and their
Special Counsel in connection with the registration or qualification (or
exemption from such registration or qualification) of such Registrable
Securities for offer and sale under the securities or Blue Sky laws of such
jurisdictions within the United States as any Holder requests in writing, to
keep each such registration or qualification (or exemption therefrom) effective
during the Effectiveness Period and to do any and all other acts or things
necessary or advisable to enable the disposition in such jurisdictions of the
Registrable Securities covered by a Registration Statement; provided, that the
Company shall not be required to qualify generally to do business in any
jurisdiction where it is not then so qualified or subject the Company to any
material tax in any such jurisdiction where it is not then so subject.

      (g) Cooperate with the Holders to facilitate the timely preparation and
delivery of certificates representing Registrable Securities to be delivered to
a transferee pursuant to a Registration Statement, which certificates shall be
free, to the extent permitted by the Purchase Agreement, of all restrictive
legends, and to enable such Registrable Securities to be in such denominations
and registered in such names as any such Holders may request.

      (h) Upon the occurrence of any event contemplated this Section 3, as
promptly as reasonably possible, prepare a supplement or amendment, including a
post-effective amendment, to a Registration Statement or a supplement to the
related Prospectus or any document incorporated or deemed to be incorporated
therein by reference, and file any other required document so that, as
thereafter delivered, neither a Registration Statement nor such Prospectus will
contain an untrue statement of a material fact or omit to state a material fact
required to be stated therein or necessary to make the statements therein, in
light of the circumstances under which they were made, not misleading.



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      (i) Comply with all applicable rules and regulations of the Commission.

      (j) Use its best efforts to avoid the issuance of, or, if issued, obtain
the withdrawal of (i) any order suspending the effectiveness of a Registration
Statement, or (ii) any suspension of the qualification (or exemption from
qualification) of any of the Registrable Securities for sale in any
jurisdiction, at the earliest practicable moment.

      (k) Furnish to each Holder and their Special Counsel, without charge, at
least one conformed copy of each Registration Statement and each amendment
thereto, including financial statements and schedules, all documents
incorporated or deemed to be incorporated therein by reference, and all exhibits
to the extent requested by such Person (including those previously furnished or
incorporated by reference) promptly after the filing of such documents with the
Commission.

   4. Registration Expenses. All fees and expenses incident to the performance
of or compliance with this Agreement by the Company shall be borne by the
Company whether or not any Registrable Securities are sold pursuant to the
Registration Statement. The fees and expenses referred to in the foregoing
sentence shall include, without limitation, (i) all registration and filing fees
(including, without limitation, fees and expenses (A) with respect to filings
required to be made with the Principal Market on which the Common Stock is then
listed for trading, and (B) in compliance with applicable state securities or
Blue Sky laws (including, without limitation, fees and disbursements of counsel
for the Company in connection with Blue Sky qualifications or exemptions of the
Registrable Securities and determination of the eligibility of the Registrable
Securities for investment under the laws of such jurisdictions as requested by
the Holders )), (ii) printing expenses (including, without limitation, expenses
of printing certificates for Registrable Securities and of printing prospectuses
requested by the Holders), (iii) messenger, telephone and delivery expenses,
(iv) fees and disbursements of counsel for the Company and Special Counsel for
the Holders (which fees of Special Counsel, in addition to the fees and expenses
permitted under the Purchase Agreement, shall not exceed $7,500) and (v) fees
and expenses of all other Persons retained by the Company in connection with the
consummation of the transactions contemplated by this Agreement. In addition,
the Company shall be responsible for all of its internal expenses incurred in
connection with the consummation of the transactions contemplated by this
Agreement (including, without limitation, all salaries and expenses of its
officers and employees performing legal or accounting duties), the expense of
any annual audit and the fees and expenses incurred in connection with the
listing of the Registrable Securities on any securities exchange as required
hereunder.

   5. Indemnification

      (a) Indemnification by the Company. The Company shall, notwithstanding any
termination of this Agreement, indemnify and hold harmless each Holder, the
officers, directors, agents, counsel, investment advisors and employees of each
of them, each Person who controls any such Holder (within the meaning of Section
15 of the Securities Act or Section 20 of the Exchange Act) and the officers,
directors, agents and employees


                                       7

of each such controlling Person, to the fullest extent permitted by applicable
law, from and against any and all losses, claims, damages, liabilities, costs
(including, without limitation, costs of preparation and attorneys' fees) and
expenses (collectively, "Losses"), as incurred, arising out of or relating to
any untrue or alleged untrue statement of a material fact contained in a
Registration Statement, any Prospectus or any form of prospectus or in any
amendment or supplement thereto or in any preliminary prospectus, or arising out
of or relating to any omission or alleged omission of a material fact required
to be stated therein or necessary to make the statements therein (in the case of
any Prospectus or form of prospectus or supplement thereto, in light of the
circumstances under which they were made) not misleading, except to the extent,
but only to the extent, that (1) such untrue statements or omissions are based
solely upon information regarding such Holder furnished in writing to the
Company by such Holder expressly for use therein, or to the extent that such
information relates to such Holder or such Holder's proposed method of
distribution of Registrable Securities and was reviewed and expressly approved
in writing by such Holder expressly for use in a Registration Statement, such
Prospectus or such form of Prospectus or in any amendment or supplement thereto
or (2) in the case of an occurrence of an event of the type specified in Section
3(d)(ii)-(vi), the use by such Holder of an outdated or defective Prospectus
after the Company has notified such Holder in writing that the Prospectus is
outdated or defective and prior to the receipt by such Holder of the Advice
contemplated in Section 6(e). The Company shall notify the Holders promptly of
the institution, threat or assertion of any Proceeding of which the Company is
aware in connection with the transactions contemplated by this Agreement.

      (b) Indemnification by Holders. Each Holder shall, severally and not
jointly, indemnify and hold harmless the Company, its directors, officers,
agents, counsel and employees, each Person who controls the Company (within the
meaning of Section 15 of the Securities Act and Section 20 of the Exchange Act),
and the directors, officers, agents or employees of such controlling Persons, to
the fullest extent permitted by applicable law, from and against all Losses (as
determined by a court of competent jurisdiction in a final judgment not subject
to appeal or review) arising solely out of or based solely upon any untrue
statement of a material fact contained in any Registration Statement, any
Prospectus, or any form of prospectus, or in any amendment or supplement
thereto, or arising solely out of or based solely upon any omission of a
material fact required to be stated therein or necessary to make the statements
therein not misleading to the extent, but only to the extent, that such untrue
statement or omission is contained in any information so furnished in writing by
such Holder to the Company specifically for inclusion in such Registration
Statement or such Prospectus or to the extent that (1) such untrue statements or
omissions are based solely upon information regarding such Holder furnished in
writing to the Company by such Holder expressly for use therein, or to the
extent that such information relates to such Holder or such Holder's proposed
method of distribution of Registrable Securities and was reviewed and expressly
approved in writing by such Holder expressly for use in the Registration
Statement, such Prospectus or such form of Prospectus or in any amendment or
supplement thereto or (2) such Holder's failure to comply with the prospectus
delivery requirements of the Securities Act, including in the case of an
occurrence of an event of the type specified in Section 3(d)(ii)-


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(vi), the use by such Holder of an outdated or defective Prospectus after the
Company has notified such Holder in writing that the Prospectus is outdated or
defective and prior to the receipt by such Holder of the Advice contemplated in
Section 6(e). In no event shall the liability of any selling Holder hereunder be
greater in amount than the dollar amount of the net proceeds received by such
Holder upon the sale of the Registrable Securities giving rise to such
indemnification obligation.

      (c) Conduct of Indemnification Proceedings. If any Proceeding shall be
brought or asserted against any Person entitled to indemnity hereunder (an
"Indemnified Party"), such Indemnified Party shall promptly notify the Person
from whom indemnity is sought (the "Indemnifying Party") in writing, and the
Indemnifying Party shall assume the defense thereof, including the employment of
counsel reasonably satisfactory to the Indemnified Party and the payment of all
fees and expenses incurred in connection with defense thereof; provided, that
the failure of any Indemnified Party to give such notice shall not relieve the
Indemnifying Party of its obligations or liabilities pursuant to this Agreement,
except (and only) to the extent that it shall be finally determined by a court
of competent jurisdiction (which determination is not subject to appeal or
further review) that such failure shall have proximately and materially
adversely prejudiced the Indemnifying Party.

      An Indemnified Party shall have the right to employ separate counsel in
any such Proceeding and to participate in the defense thereof, but the fees and
expenses of such counsel shall be at the expense of such Indemnified Party or
Parties unless: (1) the Indemnifying Party has agreed in writing to pay such
fees and expenses; or (2) the Indemnifying Party shall have failed promptly to
assume the defense of such Proceeding and to employ counsel reasonably
satisfactory to such Indemnified Party in any such Proceeding; or (3) the named
parties to any such Proceeding (including any impleaded parties) include both
such Indemnified Party and the Indemnifying Party, and such Indemnified Party
shall have been advised by counsel that a conflict of interest is likely to
exist if the same counsel were to represent such Indemnified Party and the
Indemnifying Party (in which case, if such Indemnified Party notifies the
Indemnifying Party in writing that it elects to employ separate counsel at the
expense of the Indemnifying Party, the Indemnifying Party shall not have the
right to assume the defense thereof and such counsel shall be at the expense of
the Indemnifying Party). The Indemnifying Party shall not be liable for any
settlement of any such Proceeding effected without its written consent, which
consent shall not be unreasonably withheld. No Indemnifying Party shall, without
the prior written consent of the Indemnified Party, effect any settlement of any
pending Proceeding in respect of which any Indemnified Party is a party, unless
such settlement includes an unconditional release of such Indemnified Party from
all liability on claims that are the subject matter of such Proceeding.

      All fees and expenses of the Indemnified Party (including reasonable fees
and expenses to the extent incurred in connection with investigating or
preparing to defend such Proceeding in a manner not inconsistent with this
Section) shall be paid to the Indemnified Party, as incurred, within ten
Business Days of written notice thereof to the


                                       9

Indemnifying Party (regardless of whether it is ultimately determined that an
Indemnified Party is not entitled to indemnification hereunder; provided, that
the Indemnifying Party may require such Indemnified Party to undertake to
reimburse all such fees and expenses to the extent it is finally judicially
determined that such Indemnified Party is not entitled to indemnification
hereunder).

      (d) Contribution. If a claim for indemnification under Section 5(a) or
5(b) is unavailable to an Indemnified Party (by reason of public policy or
otherwise), then each Indemnifying Party, in lieu of indemnifying such
Indemnified Party, shall contribute to the amount paid or payable by such
Indemnified Party as a result of such Losses, in such proportion as is
appropriate to reflect the relative fault of the Indemnifying Party and
Indemnified Party in connection with the actions, statements or omissions that
resulted in such Losses as well as any other relevant equitable considerations.
The relative fault of such Indemnifying Party and Indemnified Party shall be
determined by reference to, among other things, whether any action in question,
including any untrue or alleged untrue statement of a material fact or omission
or alleged omission of a material fact, has been taken or made by, or relates to
information supplied by, such Indemnifying Party or Indemnified Party, and the
parties' relative intent, knowledge, access to information and opportunity to
correct or prevent such action, statement or omission. The amount paid or
payable by a party as a result of any Losses shall be deemed to include, subject
to the limitations set forth in Section 5(c), any reasonable attorneys' or other
reasonable fees or expenses incurred by such party in connection with any
Proceeding to the extent such party would have been indemnified for such fees or
expenses if the indemnification provided for in this Section was available to
such party in accordance with its terms.

      The parties hereto agree that it would not be just and equitable if
contribution pursuant to this Section 5(d) were determined by pro rata
allocation or by any other method of allocation that does not take into account
the equitable considerations referred to in the immediately preceding paragraph.
Notwithstanding the provisions of this Section 5(d), no Holder shall be required
to contribute, in the aggregate, any amount in excess of the amount by which the
proceeds actually received by such Holder from the sale of the Registrable
Securities subject to the Proceeding exceeds the amount of any damages that such
Holder has otherwise been required to pay by reason of such untrue or alleged
untrue statement or omission or alleged omission.

      The indemnity and contribution agreements contained in this Section are in
addition to any liability that the Indemnifying Parties may have to the
Indemnified Parties.

   6. Miscellaneous

      (a) Amendments and Waivers. The provisions of this Agreement, including
the provisions of this sentence, may not be amended, modified or supplemented,
and waivers or consents to departures from the provisions hereof may not be
given, unless the same shall be in writing and signed by the Company and the
Holders of at least two-thirds of the then outstanding Registrable Securities.
Notwithstanding the foregoing, a waiver or


                                       10

consent to depart from the provisions hereof with respect to a matter that
relates exclusively to the rights of Holders and that does not directly or
indirectly affect the rights of other Holders may be given by Holders of at
least a majority of the Registrable Securities to which such waiver or consent
relates; provided, however, that the provisions of this sentence may not be
amended, modified, or supplemented except in accordance with the provisions of
the immediately preceding sentence.

      (b) No Inconsistent Agreements. Neither the Company nor any of its
subsidiaries has entered, as of the date hereof, nor shall the Company or any of
its subsidiaries, on or after the date of this Agreement, enter into any
agreement with respect to its securities, that would have the effect of
impairing the rights granted to the Holders in this Agreement or otherwise
conflicts with the provisions hereof. Except as and to the extent specified in
Schedule 6(b) hereto, neither the Company nor any of its subsidiaries has
previously entered into any agreement granting any registration rights with
respect to any of its securities to any Person that have not been satisfied in
full.

      (c) No Piggyback on Registrations. Except as and to the extent specified
in Schedule 6(c) hereto, neither the Company nor any of its security holders
(other than the Holders in such capacity pursuant hereto) may include securities
of the Company in the Registration Statement other than the Registrable
Securities, and the Company shall not after the date hereof enter into any
agreement providing any such right to any of its security holders.

      (d) Compliance. Each Holder covenants and agrees that it will comply with
the prospectus delivery requirements of the Securities Act as applicable to it
in connection with sales of Registrable Securities pursuant to the Registration
Statement.

      (e) Discontinued Disposition. Each Holder agrees by its acquisition of
such Registrable Securities that, upon receipt of a notice from the Company of
the occurrence of any event of the kind described in Sections 3(d), such Holder
will forthwith discontinue disposition of such Registrable Securities under a
Registration Statement until such Holder's receipt of the copies of the
supplemented Prospectus and/or amended Registration Statement contemplated by
Section 3(h), or until it is advised in writing (the "Advice") by the Company
that the use of the applicable Prospectus may be resumed, and, in either case,
has received copies of any additional or supplemental filings that are
incorporated or deemed to be incorporated by reference in such Prospectus or
Registration Statement. The Company may provide appropriate stop orders to
enforce the provisions of this paragraph.

      (f) Piggy-Back Registrations. If at any time during the Effectiveness
Period there is not an effective Registration Statement covering all of the
Registrable Securities and the Company shall determine to prepare and file with
the Commission a registration statement relating to an offering for its own
account or the account of others under the Securities Act of any of its equity
securities, other than on Form S-4 or Form S-8 (each as promulgated under the
Securities Act) or their then equivalents relating to equity securities to be
issued solely in connection with any acquisition of any entity or business


                                       11

or equity securities issuable in connection with stock option or other employee
benefit plans, then the Company shall send to each Holder written notice of such
determination and, if within fifteen days after receipt of such notice, any such
Holder shall so request in writing, the Company shall include in such
registration statement all or any part of such Registrable Securities such
holder requests to be registered; provided, that, the Company shall not be
required to register any Registrable Securities pursuant to this Section 6(f)
that are eligible for resale pursuant to Rule 144(k) promulgated under the
Securities Act.

      (g) Notices. Any and all notices or other communications or deliveries
required or permitted to be provided hereunder shall be delivered as set forth
in the Purchase Agreement.

      (h) Successors and Assigns. This Agreement shall inure to the benefit of
and be binding upon the successors and permitted assigns of each of the parties
and shall inure to the benefit of each Holder. The Company may not assign its
rights or obligations hereunder without the prior written consent of each
Holder. Each Holder may assign their respective rights hereunder in the manner
and to the Persons as permitted under the Purchase Agreement.

      (i) Counterparts. This Agreement may be executed in any number of
counterparts, each of which when so executed shall be deemed to be an original
and, all of which taken together shall constitute one and the same Agreement. In
the event that any signature is delivered by facsimile transmission, such
signature shall create a valid binding obligation of the party executing (or on
whose behalf such signature is executed) the same with the same force and effect
as if such facsimile signature were the original thereof.

      (j) Governing Law. All questions concerning the construction, validity,
enforcement and interpretation of this Agreement shall be governed by and
construed and enforced in accordance with the internal laws of the State of New
York, without regard to the principles of conflicts of law thereof. Each party
hereby irrevocably submits to the exclusive jurisdiction of the state and
federal courts sitting in the City of New York, borough of Manhattan, for the
adjudication of any dispute hereunder or in connection herewith or with any
transaction contemplated hereby or discussed herein, and hereby irrevocably
waives, and agrees not to assert in any suit, action or proceeding, any claim
that it is not personally subject to the jurisdiction of any such court, that
such suit, action or proceeding is improper. Each party hereby irrevocably
waives personal service of process and consents to process being served in any
such suit, action or proceeding by mailing a copy thereof to such party at the
address in effect for notices to it under this Agreement and agrees that such
service shall constitute good and sufficient service of process and notice
thereof. Nothing contained herein shall be deemed to limit in any way any right
to serve process in any manner permitted by law. Each party hereto hereby
irrevocably waives, to the fullest extent permitted by applicable law, any and
all right to trial by jury in any legal proceeding arising out of or relating to
this Agreement or the transactions contemplated hereby. If either party shall
commence a Proceeding to enforce any provisions of this Agreement, then the
prevailing party in such Proceeding shall be


                                       12

reimbursed by the other party for its attorneys fees and other costs and
expenses incurred with the investigation, preparation and prosecution of such
Proceeding.

      (k) Cumulative Remedies. The remedies provided herein are cumulative and
not exclusive of any remedies provided by law.

      (l) Severability. If any term, provision, covenant or restriction of this
Agreement is held by a court of competent jurisdiction to be invalid, illegal,
void or unenforceable, the remainder of the terms, provisions, covenants and
restrictions set forth herein shall remain in full force and effect and shall in
no way be affected, impaired or invalidated, and the parties hereto shall use
their reasonable efforts to find and employ an alternative means to achieve the
same or substantially the same result as that contemplated by such term,
provision, covenant or restriction. It is hereby stipulated and declared to be
the intention of the parties that they would have executed the remaining terms,
provisions, covenants and restrictions without including any of such that may be
hereafter declared invalid, illegal, void or unenforceable.

      (m) Headings. The headings in this Agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof.

      (n) Independent Nature of Purchasers' Obligations and Rights. The
obligations of each Purchaser hereunder is several and not joint with the
obligations of any other Purchaser hereunder, and no Purchaser shall be
responsible in any way for the performance of the obligations of any other
Purchaser hereunder. Nothing contained herein or in any other agreement or
document delivered at any closing, and no action taken by any Purchaser pursuant
hereto or thereto, shall be deemed to constitute the Purchasers as a
partnership, an association, a joint venture or any other kind of entity, or
create a presumption that the Purchasers are in any way acting in concert with
respect to such obligations or the transactions contemplated by this Agreement.
Each Purchaser shall be entitled to protect and enforce its rights, including
without limitation the rights arising out of this Agreement, and it shall not be
necessary for any other Purchaser to be joined as an additional party in any
proceeding for such purpose.

                              ********************



                                       13

      IN WITNESS WHEREOF, the parties have executed this Registration Rights
Agreement as of the date first written above.

                            AUTHENTIDATE HOLDING CORP.

                            By:
                               --------------------------------------
                               Name:
                               Title:


                            OMICRON MASTER TRUST

                            By: Omicron Capital L.P., as subadvisor
                            By: Omicron Capital Inc., its general partner

                            By:
                               --------------------------------------
                               Name:  Bruce Bernstein
                               Title: President

                            GRUBER & MCBAIN CAPITAL MANAGEMENT

                            By:
                               --------------------------------------
                               Name:
                               Title:

                            MIDSUMMER INVESTMENT, LTD.

                            By:
                               --------------------------------------
                               Name:
                               Title:



                                       14

                             [SIGNATURE PAGE CONT.]

ISLANDIA, L.P.

By:
   ------------------------------
    Name:
    Title:










                                       15

                              PLAN OF DISTRIBUTION

      The Selling Stockholders and any of their pledgees, assignees and
successors-in-interest may, from time to time, sell any or all of their shares
of Common Stock on any stock exchange, market or trading facility on which the
shares are traded or in private transactions. These sales may be at fixed or
negotiated prices. The Selling Stockholders may use any one or more of the
following methods when selling shares:

   -  ordinary brokerage transactions and transactions in which the
      broker-dealer solicits purchasers;

   -  block trades in which the broker-dealer will attempt to sell the shares as
      agent but may position and resell a portion of the block as principal to
      facilitate the transaction;

   -  purchases by a broker-dealer as principal and resale by the broker-dealer
      for its account;

   -  an exchange distribution in accordance with the rules of the applicable
      exchange;

   -  privately negotiated transactions;

   -  short sales

   -  broker-dealers may agree with the Selling Stockholders to sell a specified
      number of such shares at a stipulated price per share;

   -  a combination of any such methods of sale; and

   -  any other method permitted pursuant to applicable law.

   The Selling Stockholders may also sell shares under Rule 144 under the
Securities Act, if available, rather than under this prospectus. Broker-dealers
engaged by the Selling Stockholders may arrange for other brokers-dealers to
participate in sales. Broker-dealers may receive commissions or discounts from
the Selling Stockholders (or, if any broker-dealer acts as agent for the
purchaser of shares, from the purchaser) in amounts to be negotiated. The
Selling Stockholders do not expect these commissions and discounts to exceed
what is customary in the types of transactions involved.

      The selling stockholder may from time to time pledge or grant a security
interest in some or all of the Shares or common stock or Warrant owned by them
and, if they default in the performance of their secured obligations, the
pledgees or secured parties may offer and sell the shares of common stock from
time to time under this prospectus, or under an amendment to this prospectus
under Rule 424(b)(3) or other applicable provision of the Securities Act of 1933
amending the list of selling stockholders to


                                       16

include the pledgee, transferee or other successors in interest as selling
stockholders under this prospectus.

      The selling stockholders also may transfer the shares of common stock in
other circumstances, in which case the transferees, pledgees or other successors
in interest will be the selling beneficial owners for purposes of this
prospectus.

      The Selling Stockholders and any broker-dealers or agents that are
involved in selling the shares may be deemed to be "underwriters" within the
meaning of the Securities Act in connection with such sales. In such event, any
commissions received by such broker-dealers or agents and any profit on the
resale of the shares purchased by them may be deemed to be underwriting
commissions or discounts under the Securities Act. The Selling Stockholders have
informed the Company that it does not have any agreement or understanding,
directly or indirectly, with any person to distribute the Common Stock.

      The Company is required to pay all fees and expenses incident to the
registration of the shares. The Company has agreed to indemnify the Selling
Stockholders against certain losses, claims, damages and liabilities, including
liabilities under the Securities Act.







                                       17