Abstract:

In this paper, by combining vector space secret sharing with proxy signature, we present a vector space secret sharing scheme,the threshold proxy signature. In this scheme, there is a trusted share distribution center, and the threshold proxy signature can be easily produced if an authorized subset of participants pool their secret shares, and it is impossible for them to generate a proxy signature if an unauthorized subset of participants pool their secret shares. The validity of the partial signature and the threshold proxy signature can be verified by means of verification equations. Moreover the suspected forgery can be traced and the malicious participants can be caught in this scheme. None of the possible attacks can successfully break this scheme.

Key words: vector space secret sharing;threshold proxy signature;bilinear pairing;strong unforgeability