SYSTEM AND METHOD FOR SEQUENTIAL DATA SIGNATURES

摘要

A digital message (m) is signed and, if a request is approved, receives a time stamp (T). The request is computed as a first function of the message and a current one of a sequence of passwords (z l , …, z i) computed such that each password corresponds to an index unit. The request (ϰ) is submitted to a signature server (500). If the request is approved, the signature server returns a current time-stamp (T). Each of the passwords may be computed as a function, such as a hash function, pseudo-random function, or encryption function, of the subsequent password. At least one hash tree uses at least a subset of the passwords as inputs to a hash tree used to verify the passwords.