G_{its}^2 VSR: An Information Theoretical Secure Verifiable Secret Redistribution Protocol for Long-term Archival Storage

Abstract

Protocols for secure archival storage are becoming increasingly important as the use of digital storage for sensitive documents is gaining wider practice. In [8], Wong et al. combined verifiable secret sharing with proactive secret sharing without reconstruction and proposed a verifiable secret redistribution protocol for long term storage. However, their protocol requires that each of the receivers is honest during redistribution. We proposed [3] an extension to their protocol wherein we relaxed the requirement that all the recipients should be honest to the condition that only a simple majority amongst the recipients need to be honest during the re(distribution) processes. Further, both of these protocols make use of Feldman 's approach for achieving integrity during the (re)distribution processes. In this paper, we present a revised version of our earlier protocol, and its adaptation to incorporate Pedersen 's approach instead of Feldman's thereby achieving information theoretic secrecy while retaining integrity guarantees.