Fortifying PDF documents

Officials at Adobe Systems Inc. will provide tighter security for electronic documents later this year by offering software that prevents people without the proper credentials from altering files.

Adobe officials are developing a security policy server for the company's popular Acrobat software. The software uses PDFs, which allow electronically exchanged files to be viewed and printed on a variety of platforms.

Problems with maintaining the confidentiality of electronic documents and preventing document tampering are on the rise, said John Landwehr, Adobe's group manager for security solutions and strategy. Although he would not divulge the details of any specific document tampering incident in the federal government, Landwehr said cases of document spoofing represent a growing problem for government and corporate offices.

"It's definitely well above the hundreds, and these are just the ones that we've heard about," Landwehr said. Adobe officials vowed in February to solve some of the PDF file security problems with a policy server. Adobe's executive and legal departments have been using the software for the past nine months, but Adobe officials will not begin beta tests with government and corporate users until this summer, Landwehr said.

The policy server would offer security auditing and access and authorization controls for PDF documents, but it's the ubiquity of such documents that makes Adobe's work interesting, said Paul Proctor, vice president of security and risk strategies at Meta Group Inc. A content-management system offers similar controls, but usually only within the system's virtual file cabinet, he said.

With the Adobe policy server, Abobe officials are promising the ability "to deliver a document to somebody, to know that you delivered it to them and to restrict them from giving it to other people," Proctor said. "That's huge."

If a document ends up in the wrong hands, that person simply can't open it.

Although this capability may sound complicated, it has to be easy to use, Landwehr said. "Two clicks, and I can protect a document," he said. If such products are not painless, employees will try to avoid applying security policies to the documents they create.

Adobe's policy server could also be used to prevent document tampering through the use of public-key infrastructure technology.

If PKI digital signatures on PDF documents are set up and checked properly, unwanted users cannot easily tamper with the documents, said William Burr, manager of the security technology group at the National Institute of Standards and Technology. "It can be pretty close to bulletproof," he added.

But most security products are not bulletproof, and the policy server is no exception, Proctor said. To achieve the highest levels of document security, he said, document creators would have to set a policy that required authorized users to notify the policy server every time they try to open the documents.