Publication by Kanta MATSUURA

R. Zhang, M. Kudoh, K. Matsuura and H. Imai. ``Instance Revocation of Digital Signature and Its Applications'', Proc. of the 2002 Symposium on Cryptography and Information Security (SCIS2002), Vol.II, pp.1143-1148, Jan. 2002. (Full text (PDF)): (Abstract) This work is to have significant instance-management functions regarding digital signature. While a wide variety of the certificate revocation technology has been studied, an idea for instance revocation of digital signature without revoking the certificate has not been investigated. We show that the problem of the instance signature revocation is equivalent to the problem when and how the non-repudiatable property can be removed from the signature. We present a signature revocation model based on the signature revocation token and its revocation protocols, which enables the notion of instance revocation of digital signature on top of the existing signature schemes. Using our proposed model and protocols, the signer can revoke his previously signed message under the mutual consent with the signature receiver. We also present a construction for the privacy-enhanced digital signature that allows the signer to control the universal verifiability of the signature.; (Keywords) Instance management, signature revocation