Efficient unconditionally secure multiparty computation using ramp scheme

摘要

Multiparty protocols allow a group of players to evaluate jointly the output of a function while maintaining the secrecy of privately held inputs, using a (k,n)-threshold secret sharing scheme. The (k,n)-threshold secret sharing scheme is inefficient in computation and communication cost, as each share cannot be smaller than the original secret. We propose efficient protocols adopting a ramp scheme for the secret sharing. In this paper, we propose an unconditionally secure protocol, while we have already proposed a protocol assuming computational complexity in [5].