Digital Document Signing: Vulnerabilities and Solutions

Digital signature is the key issue in a number of innovative pro- cesses, such as dematerialization, e-government, e-commerce, and e-banking. Digital signature ensures both the identity of the user and the integrity of the digital docu- ment the user signs. However, despite the robustness of the underlying cryptographic primitives, a number of vulnerabilities derive from the radical difference between handwritten signature on papers and signature on digital documents. Indeed, digital documents are not directly observable because humans need a tool to interpret the bits of the document and to represent the corresponding information. The aim of this paper is to focus on the vulnerabilities of digital signature deriving from the “unobservability” of electronic documents. Possible mechanisms to contrast such vulnerabilities are also proposed, highlighting their positive and negative points under a perspective that does not ignore both practical and regulatory aspects.