A decryption circuit for generating a decrypted data signal and a
complementary decrypted data signal from a key. In addition, a means for
performing a linkage specification so as to generate the logic signal and
the complementary logic signal from the decrypted data signal and the
complementary decrypted data signal in accordance with the linkage
specification. In addition, an encryption means for generating an
encrypted logic signal from the key and from the logic signal.