THE TRANSFERABILITY OF THIS WARRANT IS RESTRICTED AS PROVIDED IN SECTION 3

Exhibit 4.3

NEITHER THIS WARRANT NOR THE SECURITIES ISSUABLE UPON EXERCISE THEREOF HAVE BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR QUALIFIED UNDER ANY STATE SECURITIES LAWS. NO SALE OR DISPOSITION OF THIS WARRANT OR ANY SUCH SECURITIES MAY BE EFFECTED EXCEPT (i) PURSUANT TO EFFECTIVE REGISTRATION STATEMENTS RELATED THERETO, (ii) PURSUANT TO AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY THAT AN APPLICABLE EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF SUCH ACT AND SUCH LAWS, OR (iii) FOLLOWING RECEIPT OF NO-ACTION LETTERS FROM THE APPROPRIATE GOVERNMENTAL AUTHORITIES.

THE TRANSFERABILITY OF THIS WARRANT IS

RESTRICTED AS PROVIDED IN SECTION 3

Warrant No. 2013-17

Number of Shares of Common Stock: 500,000

AUTHENTIDATE HOLDING CORP.

COMMON STOCK PURCHASE WARRANT

For good and valuable consideration, the receipt of which is hereby acknowledged by AUTHENTIDATE HOLDING CORP., a Delaware corporation (the “Company”), HEALTH MANAGEMENT INFORMATION GROUP, LLC (the “Holder”), is hereby granted the right to purchase, at any time from and after the 19^th day of March, 2014 (the “Initial Exercise Date”) until 5:00 P.M., New York City time, on September 19, 2018 (the “Warrant Exercise Term”), up to FIVE HUNDRED THOUSAND (500,000) fully-paid and non-assessable shares of the Company’s Common Stock, $.001 par value per share (“Common Stock”) subject to and in accordance with the vesting provisions set forth below in Section 1.1. This Common Stock Purchase Warrant (the “Warrant”) has been issued as of the 19^th day of September, 2013 (the “Issue Date”).

1.1 Exercise Price, Vesting and Mechanics of Exercise.

(a) During the Warrant Exercise Term, this Warrant shall be exercisable at a per share price of $1.34 (the “Exercise Price”), subject to adjustment as provided in Section 2 hereof, payable by wire transfer or by certified or official bank check in immediately available U.S. funds. Subject to the vesting conditions set forth below, the rights represented by this Warrant may be exercised in whole or in part at any time during the Warrant Exercise Term, upon surrender of the original of this warrant certificate with the annexed Notice of Exercise duly executed, together with payment of the Exercise Price for the shares of Common Stock purchased at the Company’s principal executive offices. Upon the occurrence of all of such events, the registered Holder of the Warrant shall be entitled to receive a certificate or certificates for the shares of Common Stock so purchased (the “Warrant Shares”). This Warrant has been issued by the Company pursuant to that certain agreement between the Company and the original Holder dated as of March 18, 2013 (the “Agreement”), and is subject to the certain vesting, forfeiture and other provisions as set forth below and in the Agreement. This Warrant may be exercised by the Holder as to the whole or any lesser number of an aggregate of the Warrant Shares covered hereby in accordance with the vesting requirements set forth in Section 1.1(b) of this Warrant.

(b) From and after the Initial Exercise Date, this Warrant may be exercised to purchase such number of Warrant Shares as may be vested in accordance with the following requirements. Commencing on Issue Date, the Warrant Shares shall vest in installments of 50,000

Warrant Shares for each $2,000,000 of Service Revenues (as defined below) recognized by the Company (in accordance with U.S. generally accepted accounting principles) during the Warrant Exercise Term from Customers (as defined below).

(i) As used in this Warrant, the phrase “Customer(s)” means a third party that satisfies all of the following criteria: (A) is either (I) a hospital or hospital system indentified in the Agreement or expressly contemplated by the Agreement or (II) such other third party expressly contemplated by the Agreement, (B) that enters into a definitive agreement with the Company in accordance with the requirements of the Agreement, (C) which definitive agreement provides for their use of those of the Company’s products and services contemplated by the Agreement, and (D) pursuant to which definitive agreement the Company recognizes (in accordance with U.S. generally accepted accounting principles) revenues derived from the sale or license of its products and/or services.

(ii) As used in this Warrant, the phrase “Service Revenues” means revenues recognized by the Company (in accordance with U.S. generally accepted accounting principles) received from Customers as contemplated by the Agreement, and which (A) are actually billed and collected from the Customer and (B) are recognized during the Warrant Exercise Term. Notwithstanding the foregoing, however, “Service Revenues” shall exclude all amounts billed to, or received from, Customers for hardware, set-up, customization and related projects. Service Revenues shall be measured each fiscal quarter of the Company upon its filing of the required periodic reports with the SEC.

(c) For purposes of clarity, it is agreed that: (i) 50,000 Warrant Shares shall vest immediately when the Company recognizes Service Revenues of at least $2,000,000 during the Warrant Exercise Term; and (ii) for each additional $2,000,000 in Service Revenues recognized by the Company during the Warrant Exercise Term, an additional 50,000 Warrant Shares shall vest until a total of $20,000,000 of Service Revenues are recognized by the Company (during the Warrant Exercise Term) and 500,000 Warrant Shares have vested.

(d) The purchase rights represented by this Warrant are exercisable at the option of the Holder hereof, in whole or in part (but not as to fractional shares of the Common Stock) during any period in which this Warrant may be exercised as set forth above. In the case of the purchase of less than all the shares of Common Stock purchasable under this Warrant, the Company shall cancel this Warrant upon the surrender thereof and, upon the written request of the Holder, the Company shall execute and deliver a new Warrant of like tenor for the balance of the shares of Common Stock purchasable hereunder.

1.2 Delivery of Warrant Shares. Certificates for Warrant Shares purchased hereunder shall be transmitted by the transfer agent of the Company to the Holder by physical delivery to the address specified by the Holder in the Notice of Exercise within three Business Days from the delivery to the Company of the Notice of Exercise, surrender of this Warrant and payment of the aggregate Exercise Price as set forth above. This Warrant shall be deemed to have been exercised on the date on which this Warrant is surrendered and payment of the Exercise Price is received by the Company. The Warrant Shares shall be deemed to have been issued, and Holder or any other person so designated to be named therein shall be deemed to have become a holder of record of such shares for all purposes, as of the date on which all of the criteria described in the immediately preceding sentence have occurred, irrespective of the date of delivery of such certificate or certificates, except that, if the date of such surrender and payment is a date when the stock transfer books of the Company are closed, such person shall be deemed to have become the holder of such shares at the close of business on the next succeeding date on which the stock transfer books are open. As used in this Warrant, “Business Day” means a day on which banks are open for business in the city of New York.

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1.3 Transfer Taxes. The issuance of certificates for shares of Common Stock upon the exercise of this Warrant shall be made without charge to the Holder hereof of any Federal and state stamp, original issue or similar taxes which may be payable in respect of the issue of any Warrant Share. Certificates representing Warrant Shares shall be issued in the name of, or in such names as may be directed by, the Holder hereof; provided, however, that the Company shall not be required to pay any tax which may be payable in respect of any transfer involved in the issuance and delivery of such certificate in a name other than that of the Holder and the Company shall not be required to issue or deliver such certificates unless or until the person or persons requesting the issuance thereof shall have paid to the Company the amount of such tax or shall have established to the satisfaction of the Company that such tax has been paid.

1.4 Covenants by Company. The Company covenants that it will at all times reserve and keep available out of its authorized Common Stock, solely for the purpose of issuance upon exercise of this Warrant as herein provided, such number of shares of Common Stock as shall then be issuable upon the exercise of this Warrant. The Company covenants that all shares of Common Stock which shall be so issuable shall be duly and validly issued and fully-paid and non-assessable.

2.1 Stock Dividends, Subdivisions, Reclassifications or Combinations. If during the Warrant Exercise Term, the Company shall (A) declare a dividend or make a distribution on its Common Stock in shares of its Common Stock, (B) subdivide or reclassify the outstanding shares of Common Stock into a greater number of shares, or (C) combine or reclassify the outstanding Common Stock into a smaller number of shares, the Exercise Price in effect at the time of the record date for such dividend or distribution or the effective date of such subdivision, combination or reclassification shall be proportionately adjusted. Any adjustment made herein which results in a decrease (or increase) in the Exercise Price shall also effect a proportional increase (or decrease) in the number of shares of Common Stock into which this Warrant is exercisable. Successive adjustments in the Exercise Price shall be made whenever any event specified above shall occur.

2.2 Reorganization, Reclassification, Merger, Consolidation or Disposition of Assets. In case of any change in the Common Stock during the Warrant Exercise Term through merger or consolidation (where the Company is not the surviving entity), reclassification, reorganization, partial or complete liquidation, purchase of all or substantially all the assets of the Company (an “Extraordinary Transaction”), then, as a condition of such change, lawful and adequate provision will be made so that the Holder will have the right thereafter to receive upon the exercise of the Warrant the kind and amount of shares of stock or other securities or property to which he would have been entitled if, immediately prior to such event, he had held the number of Warrant Shares obtainable upon the exercise of the Warrant. In any such case, appropriate adjustment will be made in the application of the provisions set forth herein with respect to the rights and interest thereafter of the Holder, to the end that the provisions set forth herein will thereafter be applicable, as nearly as reasonably may be, in relation to any shares of stock or other property thereafter deliverable upon the exercise of the Warrant. The Company will not complete an Extraordinary Transaction during the Warrant Exercise Term unless the issuer of the shares of stock or other securities to be received by the Holder of this Warrant upon exercise, if not the Company, agrees to be bound by and comply with the provisions of this Warrant.

(a) The Holder acknowledges that he has been advised by the Company that this Warrant and the Warrant Shares issuable upon exercise thereof (collectively the “Securities”) have not been registered under the Securities Act of 1933, as amended (the “Securities Act”), that the Warrant is

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being issued, and the shares issuable upon exercise of the Warrant will be issued, on the basis of the statutory exemption provided by section 4(2) of the Securities Act relating to transactions by an issuer not involving any public offering, and that the Company’s reliance upon this statutory exemption is based in part upon the representations made by the Holder contained herein. The Holder acknowledges that he has been informed by the Company of, or is otherwise familiar with, the nature of the limitations imposed by the Securities Act and the rules and regulations thereunder on the transfer of securities. In particular, the Holder agrees that no sale, assignment or transfer of the Securities shall be valid or effective, and the Company shall not be required to give any effect to any such sale, assignment or transfer, unless (i) the sale, assignment or transfer of the Securities is registered under the Securities Act, and the Company has no obligations or intention to so register the Securities except as may otherwise be provided herein, or (ii) the Securities are sold, assigned or transferred in accordance with all the requirements and limitations of Rule 144 under the Securities Act or such sale, assignment, or transfer is otherwise exempt from registration under the Securities Act. The Holder represents and warrants that he has acquired this Warrant and will acquire the Securities for his own account for investment and not with a view to the sale or distribution thereof or the granting of any participation therein, and that he has no present intention of distributing or selling to others any of such interest or granting any participation therein. The Holder acknowledges that the Warrant and Warrant Shares must be held indefinitely unless a subsequent disposition thereof is registered under the Securities Act or registered or qualified under any applicable state securities or “blue-sky” laws or is exempt from registration and/or qualification. The Holder has no need for liquidity in its investment in the Company, and is able to bear the economic risk of such investment for an indefinite period and to afford a complete loss thereof. The Holder is an “accredited investor” as such term is defined in Rule 501 (the provisions of which are known to the Holder) promulgated under the Act.

The Holder acknowledges that the securities shall bear the following legend:

“THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933. SUCH SECURITIES MAY NOT BE SOLD OR OFFERED FOR SALE, TRANSFERRED, HYPOTHECATED OR OTHERWISE ASSIGNED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT WITH RESPECT THERETO UNDER SUCH ACT OR AN OPINION OF COUNSEL TO THE COMPANY THAT AN EXEMPTION FROM REGISTRATION FOR SUCH SALE, OFFER, TRANSFER, HYPOTHECATION OR OTHER ASSIGNMENT IS AVAILABLE UNDER SUCH ACT.”

(b) Disposition of Warrant or Warrant Shares. With respect to any offer, sale or other disposition of this Warrant or any shares of Common Stock acquired pursuant to the exercise of this Warrant prior to registration of such Warrant or shares of Common Stock, the Holder agrees to give written notice to the Company prior thereto, describing briefly the manner thereof, together with evidence, reasonably satisfactory to the Company (which shall include such representation of the transferee regarding investment intent as the Company may request, to the effect that such offer, sale or other disposition may be effected without registration or qualification under the Act as then in effect or any federal or state securities law then in effect) of this Warrant or such shares of Common Stock and indicating whether or not under the Act certificates for this Warrant or such shares of Common Stock to be sold or otherwise disposed of require any restrictive legend as to applicable restrictions on transferability in order to ensure compliance with such law. Upon receiving such written notice and reasonably satisfactory evidence, the Company, as promptly as practicable but no later than seven (7) days after receipt of the written notice, shall notify the Holder that the Holder may sell or otherwise dispose of this Warrant or such shares of Common Stock, all in accordance with the terms of the notice delivered to the Company. If the Company determines that the evidence is not reasonably satisfactory to the Company, the Company shall so notify the Holder promptly with details thereof after such

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determination has been made. Notwithstanding the foregoing, any shares of Common Stock issued upon exercise of this Warrant or such shares of Common Stock may be offered, sold or otherwise disposed of in accordance with Rule 144 under the Act and in compliance with the applicable statutory resale restrictions imposed by applicable securities laws, provided that the Company shall have been furnished with such information as the Company may reasonably request to provide a reasonable assurance that the provisions of Rule 144 and the applicable resale restrictions imposed by the securities laws have been satisfied. Each certificate representing this Warrant or the shares of Common Stock thus transferred shall bear a legend as to the applicable restrictions on transferability in order to ensure compliance with such laws, unless pursuant to an opinion of counsel for the Holder, such legend is not required in order to ensure compliance with such laws. The Company may issue stop transfer instructions to its transfer agent in connection with such restrictions.

4.1 Registration. If at any time during the Exercise Period, the Company shall determine to prepare and file with the Commission a registration statement under the Securities Act of 1933, as amended (the “Securities Act”) relating to either (i) a resale of shares of common stock or other securities of the Company by the selling security holders or, (ii) an underwritten sale of the Company’s securities solely to the extent permitted by the underwriter of the Company’s securities and, subject to existing contractual obligations of the Company, then the Company shall send to each holder of this Warrant (a “Holder”) a written notice of such determination and, if within fifteen (15) days after the date 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 Warrant Shares which such Holder requests to be registered, subject to customary underwriter cutbacks applicable to all holders of registration rights. Notwithstanding the foregoing, however, such piggyback registration rights are not applicable to: (x) any registration statement on Form S-3 (or any successor form) filed by the Company for the purpose of effecting offers and sales of securities on a continuous or delayed basis pursuant to Rule 415(a) (ix) or (x) under the Securities Act; or (y) a registration statement 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 or equity securities issuable in connection with the stock option or other employee benefit plans. The foregoing registration rights are further subject to the condition that if at any time after giving written notice of its intention to register any securities and prior to the effective date of the registration statement filed in connection with such registration, the Company shall determine for any reason not to register or to delay registration of such securities, the Company may, at its election, give written notice of such determination to such Holder and, thereupon, (A) in the case of a determination not to register, shall be relieved of its obligation to register any Warrant Shares in connection with such registration (but not from its obligation to pay expenses in accordance with Section 4.5 hereof), and (B) in the case of a determination to delay registering, shall be permitted to delay registering any Warrant Shares being registered pursuant to this Section 4.1 for the same period as the delay in registering such other securities. Notwithstanding the foregoing, the Company shall not be required to register any Warrant Shares pursuant to this Section 4.1 that are eligible for resale pursuant to Rule 144(b) promulgated under the Securities Act or that are the subject of a then effective registration statement. For the purpose of the foregoing, inclusion of the Warrant Shares by the Holder in a registration statement under a condition that the offer and/or sale of such Warrant Shares not commence until a date not to exceed 90 days from the effective date of such registration statement shall be deemed to be in compliance with this sub-paragraph.

4.2 Exceptions. The Company shall have no obligation to include Warrant Shares of any Holder in a registration statement pursuant to this Section 4, unless and until such Holder (i) in connection with any underwritten offering, agrees to enter into an underwriting agreement, a custody agreement and power of attorney and any other customary documents required in an underwritten offering

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all in customary form and containing customary provisions and (ii) regardless of whether such registration is in connection with an underwritten offering, shall have furnished the Company with all information and statements about or pertaining to such Holder in such reasonable detail and on such timely basis as is reasonably deemed by the Company to be legally required with respect to the preparation of the registration statement.

4.3 Procedures. The foregoing registration rights shall be contingent on the Holders furnishing the Company with such appropriate information (relating to the intentions of such Holders) as the Company shall reasonably request in writing. Each Holder agrees to furnish to the Company a completed selling security holder questionnaire in such form as is provided by the Company to the Holder not less than two Business Days prior to date on which the Company files the registration statement (the “Filing Date”). The Company shall not be required to include the Warrant Shares of a Holder in a registration statement for any Holder who fails to furnish to the Company a fully completed questionnaire at least two Business Days prior to the Filing Date. The Company may require each selling Holder to furnish to the Company a certified statement as to the number of shares of Common Stock beneficially owned by such Holder and, if required by the Commission, the natural persons thereof that have voting and dispositive control over the Shares. Following the effective date of such registration, the Company shall upon the request of any owner of Warrants and/or Warrant Shares forthwith supply such number of prospectuses meeting the requirements of the Securities Act as shall be requested by such owner to permit such Holder to make a public offering of all Warrant Shares from time to time offered or sold to such Holder, provided that such Holder shall from time to time furnish the Company with such appropriate information (relating to the intentions of such Holder) as the Company shall request in writing. The Company shall also use its best efforts to qualify the Warrant Shares for sale in such states as such Holder shall reasonably designate. The Company may withdraw the registration at any time.

4.4 Indemnity. The Company shall indemnify and hold harmless each such Holder and each underwriter, if any, within the meaning of the Securities Act, who may purchase from or sell for any such Holder any Warrant Shares from and against any and all losses, claims, damages and liabilities caused by any untrue statement or alleged untrue statement of a material fact contained in the registration statement or any post-effective amendment thereto or any registration statement under the Securities Act or any prospectus included therein required to be filed or furnished by reason of this Section 4 or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading except insofar as such losses, claims, damages or liabilities are caused by any such untrue statement or alleged untrue statement or omission or alleged omission based upon information furnished or required to be furnished in writing to the Company by such Holder or underwriter expressly for use therein, which indemnification shall include each person, if any, who controls any such underwriter within the meaning of the Securities Act; provided, however, that the Company shall not be obliged so to indemnify any such Holder or underwriter or controlling person unless such Holder or underwriter shall at the same time agree to indemnify the Company, its directors, each officer signing the related registration statement and each person, if any, who controls the Company within the meaning of the Securities Act, from and against any and all losses, claims, damages and liabilities caused by any untrue statement or alleged untrue statement of a material fact contained in any registration statement or any prospectus required to be filed or furnished by reason of this Section 4 or caused by any omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading insofar as such losses, claims, damages or liabilities are caused by any untrue statement or alleged untrue statement or omission based upon information furnished in writing to the Company by any such Holder or underwriter expressly for use therein.

4.5. Registration Expenses. The Holder thereof shall pay all transfer taxes, if any, relating to the sale of its shares, any registration fees, underwriting discounts or commissions or the equivalent thereof applicable to the sale of its shares and the fees of his own counsel. Other than as

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described in the preceding sentence, the Company shall pay all expenses incident to the registration of the Warrant Shares by the Company, including, without limitation, all registration and filing fees, fees and expenses of compliance with securities or blue sky laws, underwriting discounts, fees and expenses (other than any Holder’s portion of any underwriting discounts or commissions or the equivalent thereof), printing expenses, messenger and delivery expenses, and reasonable fees and expenses of counsel for the Company and the independent certified public accountants and other persons retained by the Company.

(a) A Holder shall not have the right to exercise any portion of this Warrant to the extent that after giving effect to such issuance after exercise, such Holder (together with such Holder’s affiliates), as set forth on the applicable Notice of Exercise, would beneficially own in excess of 4.99% of the number of shares of the Common Stock outstanding immediately after giving effect to such issuance. For purposes of the foregoing sentence, the number of shares of Common Stock beneficially owned by such Holder and its affiliates shall include the number of shares of Common Stock issuable upon exercise of this Warrant with respect to which the determination of such sentence is being made, but shall exclude the number of shares of Common Stock which would be issuable upon (A) exercise of the remaining, nonexercised portion of this Warrant beneficially owned by such Holder or any of its affiliates and (B) exercise or conversion of the unexercised or nonconverted portion of any other securities of the Company (including, without limitation, any other shares of Common Stock or Warrants) subject to a limitation on conversion or exercise analogous to the limitation contained herein beneficially owned by such Holder or any of its affiliates. Except as set forth in the preceding sentence, for purposes of this Section 4, beneficial ownership shall be calculated in accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), it being acknowledged by a Holder that the Company is not representing to such Holder that such calculation is in compliance with Section 13(d) of the Exchange Act and such Holder is solely responsible for any schedules required to be filed in accordance therewith.

(b) To the extent that the limitation contained in this Section 5 applies, the determination of whether this Warrant is exercisable (in relation to other securities owned by such Holder) and of which a portion of this Warrant is exercisable shall be in the sole discretion of a Holder, and the submission of a Notice of Exercise shall be deemed to be each Holder’s determination of whether this Warrant is exercisable (in relation to other securities owned by such Holder) and of which portion of this Warrant is exercisable, in each case subject to such aggregate percentage limitation, and the Company shall have no obligation to verify or confirm the accuracy of such determination. For purposes of this Section 5, in determining the number of outstanding shares of Common Stock, a Holder may rely on the number of outstanding shares of Common Stock as reflected in (A) the Company’s most recent Form 10-Q or Form 10-K, as the case may be, (B) a more recent public announcement by the Company or (C) any other notice by the Company or the Company’s transfer agent setting forth the number of shares of Common Stock outstanding. Upon the written or oral request of a Holder, the Company shall within two trading days confirm orally and in writing to such Holder the number of shares of Common Stock then outstanding. In any case, the number of outstanding shares of Common Stock shall be determined after giving effect to the conversion or exercise of securities of the Company, including this Warrant, by such Holder or its affiliates since the date as of which such number of outstanding shares of Common Stock was reported. The provisions of this Section 5 may be waived by such Holder, at the election of such Holder, upon not less than 61 days’ prior notice to the Company, and the provisions of this Section 5 shall continue to apply until such 61st day (or such later date, as determined by such Holder, as may be specified in such notice of waiver).

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6.1 All notices required or permitted hereunder shall be in writing and shall be deemed effectively given: (i) upon personal delivery to the party to be notified; (ii) when sent by confirmed electronic mail or facsimile if sent during normal business hours of the recipient, and if not, then on the next Business Day; (iii) two (2) Business Days after having been sent by registered or certified mail, return receipt requested, postage prepaid; or (iv) one (1) Business Day after deposit with a nationally recognized overnight courier, specifying next day delivery, with written verification of receipt. All communications shall be sent to the Company or to Holder, as applicable, at the respective addresses set forth on the signature page to the Agreement or at such other address(es) as they may designate, respectively, by ten (10) days advance written notice to the other party hereto.

6.2 Upon the occurrence of any adjustments pursuant to Sections 2.1 and 2.2 hereof, the Company at its expense shall, as promptly as reasonably practicable but in any event not later than 10 days thereafter, compute such adjustment in accordance with the terms hereof and furnish to Holder a certificate setting forth such adjustment and showing in detail the facts upon which such adjustment is based. If the approval of any stockholders of the Company shall be required in connection with any transaction contemplated by Section 2.2 above, then, the Company shall cause to be mailed to the Holder at least 10 calendar days prior to the effective date of such transaction, a notice stating the date on which such transaction is expected to become effective or close, and the date as of which it is expected that holders of the Common Stock of record shall be entitled to exchange their shares of the Common Stock for securities, cash or other property deliverable upon such transaction; provided that the failure to mail such notice or any defect therein or in the mailing thereof shall not affect the validity of the corporate action required to be specified in such notice.

7.1 Exchanges. This Warrant Certificate is exchangeable without expense, upon the surrender hereof by the registered Holder at the principal executive office of the Company, for a new Warrant Certificate of like tenor and date representing in the aggregate the right to purchase the same number of Warrant Shares in such denominations as shall be designated by the Holder thereof at the time of such surrender.

7.2 Loss, Destruction, Etc. Upon receipt by the Company of evidence reasonably satisfactory to it of the loss, theft, destruction or mutilation of this Warrant Certificate, and, in case of loss, theft or destruction, of indemnity or security reasonably satisfactory to it, and reimbursement to the Company of all reasonable expenses incidental thereto, and upon surrender and cancellation of the Warrants, if mutilated, the Company will make and deliver a new Warrant of like tenor, in lieu thereof and any such lost, stolen, destroyed or mutilated warrant shall thereupon become void.

The Company shall not be required to issue certificates representing fractions of the shares of Common Stock and shall not be required to issue scrip or pay cash in lieu of fractional interests, it being the intent of the parties that all fractional interests shall be eliminated by rounding any fraction up or down to the nearest whole number of shares of Common Stock.

Nothing contained in this Agreement shall be construed as conferring upon the Holder any rights whatsoever as a stockholder of the Company, either at law or in equity, including without limitation, or Holders the right to vote or to consent or to receive notice as a stockholder in respect of any meetings of stockholders for the election of directors the right to receive dividends or any other matter.

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10.1 Successors and Assigns. All the covenants and agreements made by the Company in this Warrant shall bind its successors and assigns. This Warrant shall be for the sole and exclusive benefit of the Holder and nothing in this Warrant shall be construed to confer upon any person other than the Holder any legal or equitable right, remedy or claim hereunder.

10.2 Acceptance. Receipt of this Warrant by the Holder shall constitute acceptance of and agreement to all of the terms and conditions contained herein.

10.3 No Recourse. No recourse shall be had for any claim based hereon or otherwise in any manner in respect hereof, against any incorporator, stockholder, officer or director, past, present or future, of the Company or of any predecessor corporation, whether by virtue of any constitutional provision or statute or rule of law, or by the enforcement of any assessment or penalty or in any other manner, all such liability being expressly waived and released by the acceptance hereof and as part of the consideration for the issue hereof.

10.4 Waivers and Amendments. No course of dealing between the Company and the Holder hereof shall operate as a waiver of any right of any Holder hereof, and no delay on the part of the Holder in exercising any right hereunder shall so operate. This Warrant may be amended or waived only by a written instrument executed by the Company and the Holder hereof. Any amendment shall be endorsed upon this Warrant, and all future Holders shall be bound thereby.

10.5 Governing Law. The provisions of this Warrant shall in all respects be constructed according to, and the rights and liabilities of the parties hereto shall in all respects be governed by, the laws of the State of New Jersey. This Warrant shall be deemed a contract made under the laws of the State of New Jersey and the validity of this Warrant and all rights and liabilities hereunder shall be determined under the laws of said State.

10.6 Headings. The headings of the Sections of this Warrant are inserted for convenience only and shall not be deemed to constitute a part of this Warrant.

Signature page to Common Stock Purchase Warrant follows.

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IN WITNESS WHEREOF, AUTHENTIDATE HOLDING CORP. has caused this Warrant to be executed in its corporate name by its officer, and its seal to be affixed hereto.

Dated as of: September 19, 2013

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NOTICE OF EXERCISE

Connell Corporate Center

300 Connell Drive, 5th Floor

Berkeley Heights, NJ 07922

Attention: Chief Financial Officer

The undersigned hereby elects to purchase, pursuant to the provisions of the Common Stock Warrant issued by Authentidate Holding Corp. as of September 19, 2013, and held by the undersigned, the original of which is attached hereto, and tenders herewith payment of the Exercise Price in the form of cash, via wire transfer of immediately available funds, in the amount of $         for                  shares of Common Stock.

Kindly deliver to the undersigned a certificate representing the Shares.

INSTRUCTIONS FOR DELIVERY

If such number of shares shall not be all the shares purchasable upon the exercise of the Warrants evidenced by this Warrant, a new warrant certificate for the balance of such Warrants remaining unexercised shall be registered in the name of and delivered to:

On this      day of                 , before me personally came             , to me known, who being by me duly sworn, did depose and say that he resides at                     , that he is the holder of the foregoing instrument and that he executed such instrument and duly acknowledged to me that he executed the same.

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[FORM OF ASSIGNMENT]

(To be executed by the registered holder if such holder

desires to transfer the Warrant Certificate.)

FOR VALUE RECEIVED, the undersigned Holder of this Warrant hereby sells, assigns and transfers the foregoing Warrant and all rights evidenced thereby to

and does hereby irrevocably constitute and appoint                     , Attorney, to transfer the within Warrant Certificate on the books of Authentidate Holding Corp., with full power of substitution.

NOTE: The signature to this Assignment Form must correspond with the name as it appears on the face of the Warrant, without alteration or enlargement or any change whatever. Officers of corporations and those acting in a fiduciary or other representative capacity should file proper evidence of authority to assign the foregoing Warrant.

On this      day of                 , before me personally came             , to me known, who being by me duly sworn, did depose and say that he resides at                     , that he is the holder of the foregoing instrument and that he executed such instrument and duly acknowledged to me that he executed the same.

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