Security information implementation system and lsi

A security information implementation system includes a storage section 120a for storing first encrypted security information EDK (MK) provided by encrypting final security information DK according to internal security information MK and second encrypted security information EMK (CK) provided by encrypting the internal security information MK according to conversion security information CK and an LSI 120b including a seed generation section 131 for storing a first constant value containing address information on which a conversion seed is generated based and a second constant value and a third constant value on which a test conversion seed is generated based and outputting the first constant value and the second constant value or the third constant value as the conversion seed or the test conversion seed in response to a test signal and a mode setup value; a one-way function circuit 32 for converting the conversion seed or the test conversion seed output from the seed generation section 131 according to the first encrypted security information EDK (MK) input from the storage section 120a to generate the conversion security information CK or test conversion security information; a decryption circuit 33 for decrypting the second encrypted security information EMK (CK) input from the storage section 120a using the output of the one-way function circuit 32 as a key; and a decryption circuit 34 for decrypting the first encrypted security information EDK (MK) input from the storage section 120a using the output of the decryption circuit 33 as a key.