On the Incremental Digital Signatures

摘要

The purpose of incremental cryptography is to enable updates of cryptographic forms of documents undergoing modifications, more efficiently than if we had to recompute them from scratch. This paper defines a framework for securely using a variant of the incremental hash function designed by Goi, Siddiqi and Chuah. The condition of use of their hash function is somehow impractical since they assume the blocks of the message are all distinct. In this paper we show how we can discard this strong assumption so as to construct the first practical incremental asymmetric signature scheme that keeps efficient update operations. Finally, as the proposed scheme has the defect to severely expand the signature size, we propose a solution which drastically reduces this drawback.