Service signs PDFs for integrity

GeoTrust Europe will today unveil a service to let firms digitally sign Adobe Acrobat files, allowing recipients to be confident of a document's source and that its content has not been altered by a third party.

Available immediately, Adobe Certified Document Services uses certificates issued by GeoTrust. Two versions are available: My Credential for Adobe Acrobat allows individuals to certify documents, while True Credentials for Adobe Acrobat is an enterprise version that lets administrators control which users can certify documents for the whole organisation.

The service is aimed at applications where users need to be sure of the integrity of documents, such as the electronic exchange of contracts or blueprints, and is designed to complement existing security measures such as password protection of PDF documents.

"The idea is to get organisations and government departments to make more use of electronic documents, where better security is needed," said Steve Waite, marketing director for GeoTrust Europe. The service was developed jointly by Adobe and GeoTrust, which is the second largest certificate authority after VeriSign, according to Waite.

Individuals can save documents as a certified PDF using Acrobat and a USB token device storing their certificate. Once certified, the integrity of a document can be assured, Waite said. "Adobe Reader will notify the user if a document has been amended since certification. You can also see who signed the document and when," he added.

The service also allows certificates to be revoked in case an employee with certification authority leaves the company, for example. For organisations generating a lot of documents, the enterprise version can connect with Adobe's LiveCycle Document Security to allow automated certification. Here, the certificates are stored on a PCI card installed in the server.

The My Credential for Adobe Acrobat service costs from £550 per year per user, with a sliding scale for additional users. True Credentials for Adobe Acrobat is priced based on the number of signings per year.