SCHENECTADY, N.Y.
Jun 28, 2004

Authentidate Holding Corp. (Nasdaq: ADAT) announced today that it has confirmed that the Company will be added to the Russell 2000 Index, which will also make it part of the Russell 3000 Index.

The Russell 3000 Index is the largest 3000 publicly traded companies in the United States based upon market capitalization. The Russell 2000 Index is the smallest of the 3000 and is also ranked on market capitalization.

About Authentidate Holding Corp.

Authentidate Holding Corp. (AHC) is the holding company of five business units; DocStar, Authentidate International AG, Authentidate, Inc., DJS Marketing Group/Computer Professionals International and Trac Medical Solutions, Inc. DocStar sells proprietary document imaging software that includes the Authentidate technology. Authentidate and Authentidate AG provide the authentication of digital data through its proprietary and patent pending technology. Authentidate intends to establish itself as the authority on "content security" as it is a growing sector of the electronic network security infrastructure market. DJS delivers professional services centered around technology systems integration projects, staff augmentation, out-tasking, outsourcing services and resells computer related products. Trac Medical offers an electronic form processing solution and utilizes the Authentidate technology to prove the authenticity of the content represented in completed healthcare forms.

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.