SCHENECTADY, N.Y.
Aug 3, 2004

Trac Medical Solutions, Inc. (TracMed), a subsidiary of Authentidate Holding Corp. (Nasdaq: ADAT), announced today that it has signed an agreement with Praxair Healthcare Services, a wholly owned subsidiary of Praxair, Inc. (NYSE: PX), which will enable Praxair to electronically complete Certificates of Medical Necessity (CMN's) and Written Orders using the TracMed CareCert(TM) Solution.

Praxair Healthcare Services will integrate the CareCert Solution with its HME application software throughout all US regions totaling 112 locations in 27 states.

"We've actively supported the efforts of the American Association for Homecare to implement a physician-friendly electronic signing capability and believe the CareCert solution will provide significant operational efficiencies for Praxair," said George Ristevski, president of Praxair Healthcare Services.

"We are pleased to be working with Praxair and believe the CareCert Solution will provide a major reduction in their processing costs as they grow their operations," stated John Botti, Authentidate's Chairman and CEO.

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.

About Praxair, Inc. and Praxair Healthcare Services

Praxair is the largest industrial gases company in North and South America and one of the largest worldwide, with 2003 sales of $5.6 billion. The healthcare business accounts for approximately 13% of Praxair sales worldwide.

Praxair Healthcare Services provides the homecare market with home oxygen, sleep therapy, enteral services, respiratory medications and home medical equipment. For hospitals, Praxair Healthcare Services provides a full line of Medipure(TM) medical gases, services and equipment including the Grab 'n Go(R) portable medical oxygen system. As the largest supplier of medical gases to hospitals in North America, Praxair serves over 2,000 hospitals in 45 states. More information on Praxair is available on the Internet at www.praxair.com/healthcare.

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.