BREAKUP INFORMATION GENERATING DEVICE, SECRET INFORMATION RESTORING DEVICE, BREAKUP INFORMATION GENERATING METHOD, AND SECRET INFORMATION RESTORING METHOD AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a breakup information generating device etc. capable of configuring a general (4, n) threshold secret breaking-up method so that high-speed operation can be performed using XOR and secret information and breakup information are equal in data length.;SOLUTION: The secret information is divided into (n_p-1) pieces (n_p: a prime number satisfying n_p≥n for a variance number (n)) of partial secret information K_q, dummy partial secret information K₀ is generated, and a random number R_m, a random number R₁, and a random number R_r which are independent of one another are generated. Then pieces of partial breakup information are generated through exclusive OR (XOR) operation using the dummy partial secret information K₀ and partial secret information Kq, and the random numbers R_m, R₁, and R_r, and combined to generate breakup information S_i.;COPYRIGHT: (C)2009,JPO&INPIT