Encryption Key Providing Method, Semiconductor Integrated Circuit, and Encryption Key Management Device

A semiconductor integrated circuit comprising:

• a unique data generation unit operable to generate device unique data defined uniquely by manufacturing variations;
• and
• an encryption key decrypting unit operable to decrypt an encryption key by use of encryption key information generated by an external device based on the device unique data and supplied from the external device,
• wherein the semiconductor integrated circuit generates the device unique data by means of the unique data generation unit and provides it to the external device,
• wherein the external device receives the device unique data from the semiconductor integrated circuit, and generates helper data and a device unique ID on the basis of the received device unique data, the device unique ID being a code defined individually unique to the semiconductor integrated circuit, absorbing the generation environment-caused fluctuations of the device unique data by use of the corresponding helper data, and the external device transmits the helper data to the semiconductor integrated circuit,
• wherein the semiconductor integrated circuit receives the helper data, generates a corresponding device unique ID on the basis of the received helper data and the device unique data, generates response data based on the generated device unique ID, and transmits the response data to the external device,
• wherein the external device receives the response data, and compares the received response data with the expectation value data generated on the basis of the device unique ID generated by itself,
• wherein, when the comparison result is in agreement, the external device generates a Hash function from the device unique ID and the encryption key and transmits the Hash function to the semiconductor integrated circuit, and
• wherein the semiconductor integrated circuit receives the Hash function and decrypts the encryption key on the basis of the device unique ID generated by itself and the received Hash function.

An encryption key management device coupled to a terminal device comprising:

• a unique data generation unit for generating device unique data defined uniquely by manufacturing variations;
• and an encryption key decrypting unit for decrypting an encryption key from encryption key information, the encryption key management device being operable to generate the encryption key information on the basis of the device unique data and to provide the encryption key information to the terminal device,
• wherein the terminal device generates the device unique data by means of the unique data generation unit and provides the device unique data to the encryption key management device,
• wherein the encryption key management device receives the device unique data from the terminal device, and generates helper data and a device unique ID on the basis of the received device unique data, the device unique ID being a code defined individually unique to the terminal device, absorbing the generation environment-caused fluctuations of the device unique data by use of the corresponding helper data, and the encryption key management device transmits the helper data to the terminal device,
• wherein the terminal device receives the helper data, generates a corresponding device unique ID on the basis of the received helper data and the device unique data, generates response data based on the generated device unique ID, and transmits the response data to the encryption key management device,
• wherein the encryption key management device receives the response data and compares the received response data with the expectation value data generated on the basis of the device unique ID generated by itself,
• wherein, when the comparison result is in agreement, the encryption key management device generates a Hash function from the device unique ID and the encryption key and transmits the Hash function to the terminal device, and
• wherein the terminal device receives the Hash function and decrypts the encryption key on the basis of the device unique ID generated by itself and the received Hash function.