. One-way accumulators, introduced by Benaloh and de Mare, can be used to accumulate a large number of values into a single one, which can then be used to authenticate every input value without the need to transmit the others. However, the one-way property does is not sufficient for all applications. In this paper, we generalize the definition of accumulators and define and construct a collision-free subtype. As an application, we construct a fail-stop signature scheme in which many one-time public keys are accumulated into one short public key. In contrast to previous constructions with tree authentication, the length of both this public key and the signatures can be independent of the number of messages that can be signed. 1 Introduction The security of digital signature schemes depends on so-called computational assumptions, e.g., the factoring assumption. If somebody can break the assumption on which the system is based, and if he can therefore get the private key of the signer, h...

This paper presents an overview of a general definition of digital signature