ROBUST VECTOR-SPACE SECRET SHARING SCHEMES

A secret sharing scheme makes it possible to distribute a secret value among a set of participants in such a way that only some qualified su bsets can reconstruct the value of the secret. In such a scheme, some participants can lie about the value of their shares in order to obtai n some illicit benefit. In a robust scheme, the probability that any n on-qualified coalition of participants deceive an honest participant i s bounded by some fixed value, even if they know the secret. A new rob ust secret sharing scheme is presented in this paper. This scheme impr oves the previous ones in two aspects. First, it presents a better rel ation between the information rate and the security against cheaters. Second, while the previous robust schemes were designed only for thres hold structures, the present one can realize access structures in a mo re general family. (C) 1998 Elsevier Science B.V. All rights reserved.