SECURE DYNAMIC ON CHIP KEY PROGRAMMING

• US 20130163764A1
• Filed: 03/22/2012
• Published: 06/27/2013
• Est. Priority Date: 03/28/2011
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: van den Berg, Henricus Hubertus, Gouraud, Thierry
• Granted Patent: US 10,110,380 B2
• Time in Patent Office: Days
• US Class Current: 380/278
• CPC Class Codes: G06F 21/572 Secure firmware programming, e.g. of basic input output system [BIOS]
• CPC Class Codes: H04L 2209/12 Details relating to cryptographic hardware or logic circuitry
• CPC Class Codes: H04L 2463/061 applying further key derivation, e.g. deriving traffic keys from a pair-wise master key cryptographic mechanisms or cryptographic arrangements for generation of secret information including derivation or calculation of cryptographic keys or passwords H04L9/0861
• CPC Class Codes: H04L 9/08 Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords network architectures or network communication protocols for supporting key management in a packet data network H04L63/06
• CPC Class Codes: H04L 9/0822 using key encryption key
• CPC Class Codes: H04L 9/0866 involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics
• CPC Class Codes: H04W 12/35 Protecting application or service provisioning, e.g. securing SIM application provisioning

Abstract

Provisioning an integrated circuit with confidential data, by receiving in the integrated circuit encrypted confidential data, the encrypted confidential data having been encrypted with a transport key, deriving in the integrated circuit the transport key by applying a key derivation function to a customer identifier, the customer identifier having been previously stored in the integrated circuit, decrypting in the integrated circuit the encrypted confidential data with the transport key to obtain decrypted confidential data, deriving in the integrated circuit a product key by applying a key derivation function to an integrated circuit identifier, the integrated circuit identifier having been previously stored in the integrated circuit, encrypting in the integrated circuit the decrypted confidential data with the product key to obtain re-encrypted confidential data, and storing the re-encrypted confidential data in a confidential data memory of the integrated circuit.

Claims

1. A method for provisioning an integrated circuit with confidential data, the method comprising

receiving in the integrated circuit encrypted confidential data, the encrypted confidential data having been encrypted with a transport key,

deriving in the integrated circuit the transport key by applying a key derivation function to a customer identifier, the customer identifier having been previously stored in the integrated circuit,

decrypting in the integrated circuit the encrypted confidential data with the transport key to obtain decrypted confidential data,

deriving in the integrated circuit a product key by applying a key derivation function to an integrated circuit identifier, the integrated circuit identifier having been previously stored in the integrated circuit,

encrypting in the integrated circuit the decrypted confidential data with the product key to obtain re-encrypted confidential data, and

storing the re-encrypted confidential data in a confidential data memory of the integrated circuit.

2. A method as in claim 1, wherein the re-encrypted confidential data is stored in a one-time programmable memory of the integrated circuit.

3. A method as in claim 2, wherein the re-encrypted confidential data is stored one bit at a time in the one-time programmable memory by a controller of the integrated circuit after the encrypted confidential data has been received completely.

4. A method as in claim 1, wherein

the transport key is derived with the AES algorithm from a master transport key and the customer ID,

and/or

the product key is derived with the AES algorithm from a master transport key and the integrated circuit identifier.

5. A method as in claim 4, wherein the AES algorithm is executed with an AES engine, the result of a derivation being stored in an internal register of the AES engine.

6. A method as in claim 1, wherein the confidential data comprises a secret key.

7. A method as in claim 6, further comprising verifying that the stored secret key is correct, the verifying comprising:

decrypting, with the product key and within the integrated circuit, the re-encrypted secret key stored in the confidential data memory of the integrated circuit, to obtain a resulting key,

encrypting a test vector embedded in the integrated circuit with the resulting key, to obtain a computed fingerprint, and

comparing the computed fingerprint with an expected fingerprint.

8. A method as in claim 6, wherein the confidential data comprises a checksum of the secret key, and further comprising:

during a secure boot sequence, computing a checksum of the key that is stored in the confidential memory,

compare the computed checksum to the received checksum, and

if the computed checksum and the received checksum do not match, stopping the secure boot sequence so that the integrated circuit is not usable

9. A method as in claim 1 further comprising

receiving the customer identifier, and

storing the received customer identifier one bit at a time in a one-time programmable customer memory by a controller of the integrated circuit after the customer identifier has been received completely;

and/or

receiving the integrated circuit identifier, and

storing the received integrated circuit identifier one bit at a time in a one-time programmable customer memory by a controller of the integrated circuit after the integrated circuit identifier has been received completely.

10. Method for distributing confidential data comprising

deriving a transport key by applying a key derivation function to a customer identifier,

sending the transport key to a customer,

at the customer, encrypting confidential data with the transport key,

sending the encrypted confidential data to a programming facility, and

at the programming facility, provisioning an integrated circuit with the encrypted confidential data.

11. An integrated circuit configured for provisioning with confidential data, the integrated circuit comprising

a receiver configured to receive in the integrated circuit encrypted confidential data, the encrypted confidential data having been encrypted with a transport key,

a customer identifier storage configured to a stored customer identifier,

a transport key deriver configured to derive in the integrated circuit the transport key by applying a key derivation function to the customer identifier,

a decrypting module configured to decrypt in the integrated circuit the encrypted confidential data with the transport key to obtain decrypted confidential data,

a integrated circuit identifier storage configured to stored an integrated circuit identifier,

a product key deriver configured to derive in the integrated circuit a product key by applying a key derivation function to an integrated circuit identifier,

an encrypting module to encrypt in the integrated circuit the decrypted confidential data with the product key to obtain re-encrypted confidential data, and

a confidential data memory configured to store the re-encrypted confidential data.