A new software plug-in from the United States Postal Service and Microsoft expected to be announced Tuesday is designed to provide the same kind of security for digital documents as a sealed envelope and postmark provide for paper mail.A new software plug-in from the United States Postal Service and Microsoft expected\u00a0to be announced Tuesday is designed to provide the same kind of security for digital documents as a sealed envelope and postmark provide for paper mail.Slated to be announced at the Tuesday launch for Microsoft's Office 2003, the Electronic Postmark, or EPM, extension to the new version of the software provides a way for the product's broad user base to sign and secure their documents in a way that is legally binding, according to Chuck Chamberlain, manager of business development at the USPS.The program uses technology developed by Microsoft and content security company AuthentiDate. It allows a document's creator to save a unique time- and date-stamped record based on the file's exact content in an EPM repository maintained by the USPS, according to AuthentiDate.At any time over the next seven years, subsequent recipients can check a document against the version stored in the repository to verify its authenticity, AuthentiDate said.The EPM technology complies with standards set forth in the U.S. Electronic Signatures in Global and National Commerce (ESIGN) Act of 2000, which gave legal status to digital signatures. However, without a case to test the validity of the technology, there is no way to know whether courts will accept EPMs, Chamberlain said.To use the service, customers must be running either Microsoft Office XP or Microsoft Office 2003 and download a special Office EPM extension developed by the USPS and AuthentiDate, according to Richard Reichgut, vice president of marketing at AuthentiDate.Customers must also set up an EPM account through the USPS Web site and have a valid digital certificate to sign the documents, Chamberlain said.Certificate authority GeoTrust is offering digital certificates for use with the program, but certificates from other authorities can be used as well, he said.Once installed, the Office extension adds an EPM toolbar to Microsoft Word with options for applying electronic postmarks to documents, checking the EPM on a document and managing the USPS EPM account, Reichgut said.Clicking the Apply EPM button will launch a step-by-step process for locking the document's content, signing it with the user's digital certificate and placing a record of the signed document in the USPS EPM repository. Once the document has been signed, a USPS EPM logo will be affixed to the document indicating that it is signed and the content is valid.For documents that need to be signed by multiple parties such as contracts and nondisclosure agreements, the document's author can attach multiple EPMs that must be signed by each party. The USPS EPM ensures that the document's content is not altered as it is passed from party to party, AuthentiDate said.Through their USPS account, customers can purchase blocks of EPMs, just as they would buy blocks of stamps, he said.The per-postmark price will range from 80 cents for a block of 25 EPMs to 10 cents\u00a0per EPM for a block of\u00a01 million or more electronic postmarks, he said.There is no charge for subsequent readers to verify the document, and Office 97 and 2000 users can verify EPM marked documents, though they cannot generate new electronic postmarks, Reichgut said.The Microsoft Office extension streamlines what was a loosely developed effort to bring EPM technology into the mainstream, according to the USPS' Chamberlain.The USPS and AuthentiDate only offered a software development kit that interested parties could download and use to build their own EPM plug-ins. The Office plug-in has already been integrated with Microsoft Office 2003 and tested by the USPS, Chamberlain said."Previously, buying an EPM was like buying an engine, whereas now you can buy the whole car," he said.Only a handful of organizations have tried out the EPM technology, largely because of the integration hurdles, Chamberlain said.With a new "ready to use" plug-in for Office, the Postal Service is hoping that EPM adoption picks up and that companies begin to see EPM as a replacement for slow and costly courier and fax services, especially in organizations that handle a high volume of sensitive documents such law offices and federal, state and local governments, he said.