We consider a model that is fully distributed, because we want to distribute not only the power of the proxy signer, but also the original signer ability to delegate his signing capability. Furthermore, we consider general structures, instead of only the threshold ones, for both the tolerated subsets of dishonest players and the subsets of honest players authorized to execute a valid instance of the protocol, and in both the original and the proxy signer entities. We find sufficient combinatorial conditions that these structures must satisfy in order to design a fully distributed, secure and robust proxy signature scheme for this general scenario.
We propose such a scheme for this setting. It is also based on Schnorr's signature scheme.Category / Keywords: cryptographic protocols / Proxy signature schemes, distributed cryptographic protocols, secret sharing schemes. Publication Info: To appear in the proceedings of Financial Cryptography Conference, 2003. Date: received 19 Apr 2002, last revised 11 Apr 2003 Contact author: jherranz at mat upc es Available formats: Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation Note: A revised version of this paper, entitled 'Verifiable Secret Sharing for General Access Structures, with Application to Fully Distributed Proxy Signatures', will be published by LNCS in the proceedings of FC'03. Version: 20030411:085043 (All versions of this report) Discussion forum: Show discussion | Start new discussion