Key implementation system and an LSI for realizing this, as well as the key implementation

摘要

In the key installation system for improving the confidentiality and concealment of the key, a first decrypting circuit decrypts an encrypted key EKEY 1 (EDK(MK 1 )) using an encrypted key EDK 1 (MK 1 ) as the key. A second decrypting circuit decrypts an encrypted key EMK 1 (KEY 1 ) using the output of the second decrypting circuit, that is, an internal key KEY 1 as the key. A third decrypting circuit decrypts the encrypted key EDK 1 (MK 1 ) using the output of the second decrypting circuit, that is, an internal key MK 1 as the key, to generate a final secret key DK 1.