Semiconductor device and information processing system for encrypted communication

An information processing system comprising:

• a semiconductor device;
• and
• an external device,
• wherein the external device comprises:
• an external unique information generating circuit configured to acquire a unique code as a value unique to the semiconductor device from the semiconductor device, and configured to generate external device unique information from the unique code;
• and
• a transmit information generating circuit configured to generate third information including at least second information obtained by encrypting first information stored in said external device with the use of the external device unique information, and
• wherein the semiconductor device comprises:
• a unique code storing unit configured to store the unique code;
• a received information storing unit configured to store the third information including the second information acquired from the external device;
• a principal unique information generating circuit configured to generate principal device unique information with the use of both the unique code and a portion of the third information generated by the external device;
• and
• a decrypting circuit configured to decrypt the second information with the use of the principal device unique information to recover the first information;
• an encryption processing circuit configured to perform encrypting and decrypting of communication object information with the use of the recovered first information;
• and wherein:
• the principal device unique information is distinct from all four of the unique code, the third information, the second information and the first information;
• and
• the recovered first information is not embedded in the semiconductor device.

A semiconductor device configured for encrypted communication, comprising:

• a unique code storing unit configured to store a unique code as a value unique to the semiconductor device, the unique code being an error-free value not derived from a physically unclonable function;
• a received information storing unit configured to store encrypted key information generated and outputted by an external device, the encrypted key information comprising a secret key stored in said external device and encrypted with external device unique information generated from the unique code;
• a principal unique information generating circuit configured to generate principal device unique information from the unique code stored in the unique code storing unit;
• a decrypting circuit configured to (a) acquire the principal device unique information from the principal unique information generating circuit, (b) acquire the encrypted key information directly from the received information storing unit, and (c) recover the secret key using only the principal device unique information and the encrypted key information generated by the external device;
• and
• an encryption processing circuit configured to perform encrypted communication with information encrypted using the recovered secret key;
• wherein:
• the decrypting circuit acquires the encrypted key information directly from the received information storing unit without the encrypted key information first having to be extracted from scrambled encrypted key information stored in the received information storing unit;
• the principal device unique information is distinct from all three of the unique code, the encrypted key information and the secret key;
• and
• the recovered secret key is not embedded in the semiconductor device.

An information processing system configured for encrypted communication, comprising:

• a semiconductor device comprising:
• a unique code storing unit configured to store a unique code as a value unique to the semiconductor device, the unique code being an error-free value not derived from a physically unclonable function;
• a received information storing unit configured to store encrypted key information generated and outputted by an external device, the encrypted key information comprising a secret key encrypted with external device unique information generated from the unique code;
• a principal unique information generating circuit configured to generate principal device unique information from the unique code stored in the unique code storing unit;
• a decrypting circuit configured to (a) acquire the principal device unique information from the principal unique information generating circuit, (b) acquire the encrypted key information generated by the external device, directly from the received information storing unit, and (c) recover the secret key using only the principal device unique information and the encrypted key information generated by said external device;
• and
• an encryption processing circuit configured to perform encrypted communication with information encrypted using the recovered secret key, wherein:
• the decrypting circuit acquires the encrypted key information directly from the received information storing unit without the encrypted key information first having to be extracted from scrambled encrypted key information stored in the received information storing unit;
• the recovered secret key is not embedded in the semiconductor device;
• and
• the principal device unique information is distinct from all three of the unique code, the encrypted key information and the secret key;
• and
• an external device in operative communication with the semiconductor device, wherein the external device comprises:
• an external storing unit configured to store secret key information of the semiconductor device;
• an external unique information generating circuit configured to generate said external device unique information from the unique code of the semiconductor device, after receiving said unique code from the semiconductor device;
• and
• a transmit information generating circuit configured to encrypt the stored secret key information with the external device unique information, to thereby create said encrypted key information, and output said encrypted key information to the semiconductor device.