SCHENECTADY, N.Y.

Apr 20, 2005

Authentidate Holding Corp. (Nasdaq: ADAT) announced that it has dismissed PricewaterhouseCoopers LLP as its independent registered public accounting firm. The Company stated in a filing with the Securities and Exchange Commission that it has had no disagreement with PricewaterhouseCoopers over the last two fiscal years on any matter of accounting principles or practices, financial statement disclosure or auditing scope or procedure.

The Company said that it has begun the process of selecting a new auditing firm and believes that the process will be completed in a timely manner so as not to impact the Company's reporting of financial results.

The Company stated that it will report its financial results for the quarter ended March 31, 2005 in a timely fashion and following its customary procedure, will host a conference call with investors after the results are released.

About Authentidate Holding Corp.

Authentidate Holding Corp. (AHC) is a worldwide provider of content authentication technology, a growing sector of the security software market. The Company provides secure document management solutions, enterprise network security products and services, and enterprise workflow management solutions that incorporate its proprietary authentication technology. Authentidate's offerings include the United States Postal Service Electronic Postmark Service (USPS EPM), electronic signing solutions, electronic forms processing solutions, document imaging software, and professional services related to the above.

This press release contains forward-looking statements within the meaning of section 27A of the Securities Act of 1933 and section 21E of the Securities Act of 1934. When used in this release, the words "believe," "anticipate," "think," "intend," "plan," "will be," "expect," and similar expressions identify such forward-looking statements. Such statements regarding future events and/or the future financial performance of The Company are subject to certain risks and uncertainties, which could cause actual events or the actual future results of the Company to differ materially from any forward-looking statement. Such risks and uncertainties include, among other things, the availability of any needed financing, the Company's ability to implement its business plan for various applications of its technologies, the impact of competition, the management of growth, and the other risks and uncertainties that may be detailed from time to time in the Company's reports filed with the Securities and Exchange Commission. In light of the significant risks and uncertainties inherent in the forward-looking statements included herein, the inclusion of such statements should not be regarded as a representation by the Company or any other person that the objectives and plans of the Company will be achieved.

SOURCE: Authentidate Holding Corp.