New Paradigms for Digital Signatures and Message Authentication Based on Non-Interactive Zero Knowledge Proofs

Abstract

Using non-interactive zero knowledge proofs we provide a simple new para- digm for diǵital signing and message authentication secure against adaptive chosen message attack. For digital signatures we require that the non-interactive zero knowledge proofs be publicly verifiable: they should be checkable by anyone rather than directed at a particular verifier. We accordingly show how to implement non- interactive zero knowledge proofs in a network which have the property that anyone in the network can individually check correctness while the proof is zero knowledge to any sufficiently small coalition. This enables us to implement signatures which are history independent.