Patent ID: 8074068
Filing Date: 2011-12-06
Classification: H04L

Abstract:
1. A secret sharing device of (k, n) threshold scheme (where 2≦k≦n) which individually delivers n items of shared information D( 1 ), . . . , D(n), created by dividing secret information S, to n storage units and recovers the secret information S from any k items of shared information, of the n items of shared information, comprising: a generator matrix creating device configured to create a generator matrix G of GF( a storage device which temporarily stores the secret information S before the shared information D( a divided secret data creating device configured to create n−1 items of first divided secret data K( a random number data creating device configured to create (k−1)(n−1) items of random number data R( a shared partial data calculating device configured to calculate a product of matrices with the random number data, the divided secret data (R( a header information creating device configured to assign the row number j to n−1 items of shared partial data D(j, a shared information delivering device configured to individually deliver the n items of shared information D( a recovery matrix calculating device configured to form a partial matrix G′ of k(n−1) rows×k(n−1) columns in the generator matrix G from k column vectors included in any k items of shared information of the delivered n items of shared information D( a recovering device configured to recover the secret information by multiplying the k items of shared information by the recovery matrix.