Now, people who receive certified Adobe PDF files can be automatically assured that the author’s identity has been verified by a trusted organization, and that the information within the document has not been altered, the Needham, Massachusetts-based company said in a statement announcing the CDS launch in Europe. The service has already been available in the US for several months.

There have been attempts to attach certificates to PDF documents prior to Adobe’s tie-up with GeoTrust, said Steve Waite, GeoTrust’s European marketing director, but he said it required a plug-in, and the user had to have an understanding of cryptography and digital certificates.

He said the attraction for Adobe in a deal with GeoTrust was the simplicity of SSL certification. They wanted to follow the SSL model, whereby someone receiving a certified file need only worry about opening it, he said.

In order to have certificates issued to their documents, individual users will pay 550 pounds ($895) for a credential sent to them on a USB device, with an annual renewal fee. The credential is subject to volume discounts for corporate customers requiring multiple units. Once the document has been certified, the Acrobat reader will tell you if it has been tampered with, as well as who signed it and when, Waite said, adding that GeoTrust is currently the only certification authority issuing certificates for PDFs.