Lower Bound on the Size of Shares of Nonperfect Secret Sharing Schemes
نویسندگان
چکیده
In a secret sharing scheme (SS), a dealer D distributes a piece of information Vi of a secret S to each participant Pi. If we desire that jVij < jSj, a nonperfct SS must be used, in which there exists a semi-access set C that has some information on S, but cannot recover S. This paper rst presents a general lower bound on jVij which includes the previous lower bounds for perfect SSs and nonperfect SSs as special cases. There exist, however, access hierarchies in which jVi j must be larger than the general lower bound, of course. As our second contribution, we determine the optimum size of Vi for such a certain access hierarchy.
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