SECRET DISTRIBUTION SYSTEM, SECRET DISTRIBUTION DEVICE, SECRET DISTRIBUTION METHOD, SECRET SORTING METHOD, SECRET DISTRIBUTION PROGRAM

摘要

A secret sharing system according to the present invention includes N secret sharing apparatuses. The secret sharing system according to the present invention includes fragment replacement means and reshare means. The fragment replacement means selects a number, smaller than N, of secret sharing apparatuses, generates a bijection À of {1, ..., K} †’ {1, ..., K} among the selected secret sharing apparatuses and designates a fragment a À(k)i recorded in a selected secret sharing apparatus as a k-th fragment (i represents an identification number that indicates a selected secret sharing apparatus). The reshare means performs reshare of fragments of a numeric value used as replacements by the fragment replacement means to determine new fragments.