THRESHOLD SECRET SHARING APPARATUS, THRESHOLD SECRET SHARING METHOD, SECRET INFORMATION RESTORING METHOD AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a threshold secret sharing apparatus, a threshold secret sharing method, a secret information restoring method, and a program, wherein high-speed operation is attainable by using an XOR, and a common (k, n) threshold secret sharing scheme can be constituted.;SOLUTION: Secret information K is divided into (n_p-1) pieces of partial secret information K_q (n_p is a prime number satisfying n_p≥n with respect to the number of distributions n); dummy secret information K_o is generated; mutually independent random numbers R are generated; partial distribution information is generated by an exclusive OR (XOR) operation by using the dummy secret information K_o, the partial secret information K_q, and the random numbers R; n pieces of distribution information S_i are generated by linking the partial distribution information; and the (k, n) threshold secret sharing scheme is constituted.;COPYRIGHT: (C)2008,JPO&INPIT