Dynamic content attacks on digital signatures

Abstract

Digitally signing a digital document is a straightforward procedure; however, when the digital document contains dynamic content, the digital signature may remain valid but the viewed document may not be the same as the document when viewed by the signer. Other similar problems can exist even with static documents, if the appearance of a document can be changed. In this paper, we consider previously proposed solutions for such problems, and propose a new solution. Unresolved issues and problems are also discussed.