SCHENECTADY, NY/DUSSELDORF, Frankfurt
January 12, 2004

Authentidate International AG, a subsidiary of Authentidate Holding Corp. (Nasdaq: ADAT) and Avinci AG - The Know-How Company, announced today that they have agreed to jointly market a patent processing solution which provides for the paperless tracking of the product development process with legal certainty under German law. The solution accounts for the long document retention periods in the patenting process and the consolidation of legacy electronic and paper files.

Authentidate International, AG, will generate revenue from the sale of the solution to end users through annual licensing fees as well as per transaction fees.

The solution utilizes Authentidate's qualified signatures pursuant to the German Signature Act and the European directives to provide for legal certainty of the patent documentation and combines it with Avinci's process design.

Using the solution, an end user can automatically document the progress of the development of a product and the related workflow in a legally binding way under German law. The proper use of the solution will enable customers to ensure that no document relevant for the patent is missing and that the file is complete. Using the new solution, paper documents can be scanned and fed into the electronic process using qualified signatures. At the same time, data that already exists in electronic form, such as email correspondence, can be documented with legal certainty and also be further processed. The electronic patent file also allows multiple users to work on the same patent process simultaneously and eliminates the need for paper archives

In addition to the replacement of paper archives, the solution leads to the economization of so-called WORM storage media (comparable to a CD-ROM) and their often cost-intensive migration to continually updated systems. The frequently used complex management of the patent files through barcode systems is avoided by the electronic patent file.

With this collaboratively developed solution, the two companies combine in an optimal fashion the established know-how of Authentidate, the accredited firm and specialist for signature solutions, with the comprehensive expertise of Avinci, especially from projects in the automotive and pharmaceutical industries. Thus, the design of a provider-neutral solution, which considers the individual user requirements, was made possible.

A detailed process mapping and live demonstration will be presented by Authentidate and Avinci on March 11, 2004 in Düsseldorf. Further information at www.enterprise-signature-day.com

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 a complete line of proprietary document imaging products. 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 uses the Authentidate service in the medical supply business.

About Authentidate International AG
Authentidate International AG (www.Authentidate.de), Düsseldorf, Germany is the first accredited certification provider, certified by the German Regulatory Authority for Telecommunications and Posts (RegTP), focusing legal binding timestamps compliant to the strong German electronic signature laws and European signature directives.

Authentidate is also the first accredited vendor focusing business process solutions, based on electronic signatures and timestamping technology. These solutions are featuring by easy integration, high economic efficiency, platform independence and protection of investment.

The Authentidate solutions are nationally and internationally used by well-known companies of different industries. The customers utilize the signature solutions to achieve legal security within eBilling, archiving, scanning and workflow. In addition Authentidate's technology is already integrated in different products of other manufacturers, therefore legal security for business processes is automatically available for many companies.

Authentidate is present in Europe, USA and also through partners in Asia. Authentidate Holding Corp, Inc. located in USA (New York) is listed on the Nasdaq National Market (ADAT) and in Germany (WKN 893715).

About Avinci AG
Avinci AG - The Know-How Company - is a holding company based in Frankfurt, Germany, that can be counted among the most successful consultancies at the interface between business and technology. Around 380 Avinci consultants are active throughout Europe, supporting renowned clients in the realization of their corporate strategies and the implementation of modern technologies for a lasting increase in value. Their mission: "Empowering Your Business". Over two thirds of the companies listed on Germany's DAX rely on Avinci's know-how. The consultancy was founded by former IBM managers and launched with 85 experienced consultants in Frankfurt in January 2000. Since then, additional offices have been opened in Munich, Düsseldorf, Stuttgart, Ludwigshafen, Hamburg, Berlin and Zurich. The company's dynamic growth is also reflected in its balance sheet: in 2000, Avinci's first business year, total turnover exceeded EUR 15 million; in 2001 it reached approx. EUR 35 million. The company has turned a profit in every single quarter since it was founded. Depending on the achievement of its performance targets and other parameters in the business environment, Avinci is planning an IPO in the year 2004 or later. For further information, please visit www.avinci.biz.

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.