AUTHENTICATION CIRCUIT

PROBLEM TO BE SOLVED: To provide SRAM-PUF which can stably generate correct deviation data being a correct fixed value for authentication at any number of times in arbitrary timing even when the authentication is requested at unspecified timing after normal operation is started.SOLUTION: An authentication circuit includes: a volatile memory (SRAM) 2; an information processing circuit 3 for performing authentication processing in response to a fixed value which is read from the SRAM 2 and determined by a physical characteristic; and a fixed value generation processing control circuit 4 which can perform fixed value generation processing for initializing the SRAM 2. The fixed value generation processing is to evaporate information held by the SRAM 2 and to fix information held by the SRAM 2 to a fixed value determined by the physical characteristic. The information processing circuit 3 allows a fixed value generation control circuit to start the fixed value generation processing, reads the fixed value from the SRAM after completion of the processing and performs the authentication processing in response to the fixed value which is read.