| 摘要 |
PROBLEM TO BE SOLVED: To achieve an efficient pseudo random function and an efficient frequency limited anonymous authentication system using the same. SOLUTION: A pseudo random function calculation device 1 comprises a key generating means 2, and a pseudo random function calculating means 3. The key generating means 2 generates a public key composed of a set having a first and a second factors as factors constituting elements of a finite group and a private key composed of integers, secretly stores the private key in a private key storage section 3, and discloses the public key. When an integer is inputted, the pseudo random function calculating means 3 outputs the element of the finite group as a function value of the pseudo random function. At this time, the product of a first element composed of the value obtained by calculating exponential remainder with the first factor of the public key as a base and the inputted integer as an exponential and a second element composed of the value obtained by calculating exponential remainder with the second factor of the public key as a base and an inverse of the sum of the private key and the inputted integer in the finite group as the exponential is outputted. COPYRIGHT: (C)2007,JPO&INPIT
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