HOMOMORPHIC CRYPTOGRAPHIC PROCESSING METHOD AND CRYPTOGRAPHIC PROCESSING DEVICE FOR RANDOMIZED PATTERN MATCHING

摘要

A storage (211) stores therein first cryptographic information that represents an encrypted polynomial obtained by encrypting a first polynomial that corresponds to a first vector. From a terminal that receives second cryptographic information that represents an encrypted monomial obtained by encrypting a monomial generated by use of a random number, a receiver (212) receives third cryptographic information that represents an encrypted result obtained by encrypting a result of a multiplication of a second polynomial that corresponds to a second vector by the monomial. A generator (213) generates an encrypted polynomial that includes a result of an operation of the first vector and the second vector by use of the first cryptographic information, the third cryptographic information, and information that represents the monomial. An output unit (214) outputs fourth cryptographic information that represents the encrypted polynomial generated by the generator.