One-way key fob and vehicle pairing
AssigneeTexas Instruments Incorporated
InventorJin-Meng HO
Life of this patent
Estimating the term…
Abstract
Key fob and vehicle control unit identifiers (IDs) are used for entity authentication or trust transfer to achieve a secured initial pairing. The key fob is capable of transmitting only (not receiving) and is paired with a control unit in a vehicle or with any other control device. Use of the key fob and control unit IDs prevents unauthorized pairing and access to the operation key (OpKey) that is later used for communications between the devices. Elliptical curve cryptography (ECC) is used for strong security and efficient implementation. In the pairing process, device IDs are used for entity authentication and public key cryptography is used for easy key management. Symmetric encryption is used for fast normal operation and to accommodate key fob addition or revocation after key fob loss.
Claims21
-18. (canceled)
A system comprising:
- a first device that transmits a message, the first device comprising:
- a first memory that stores an operation key, a public key, and a private key, each of the operation key, public key, and private key being associated with the first device;
- a first processor that encrypts the operation key using the private key and computes an encrypted value of the operation key using an encryption based upon the Advanced Encryption Standard (AES);
- and
- a first transmitter that transmits the message, the message including the private key-encrypted operation key and verification bits that correspond to first selected bits of the AES-encrypted value of the operation key;
- and
- a second device that receives the message, the second device comprising:
- a first receiver that receives the message;
- a second memory that stores the public key;
- and
- a second processor that decrypts the private key-encrypted operation key using the public key to recover the operation key, computes an AES-encrypted value of the recovered operation key, compares second selected bits of the AES-encrypted value of the operation key to the verification bits received in the message to determine whether the second selected bits match the verification bits, and pairs the first device with the second device when the second selected bits match the verification bits, wherein the second selected bits correspond to the first selected bits.
A system comprising:
- a first device comprising:
- a first memory that stores an operation key, a public key, a private key, and a first identifier, each of the operation key, public key, and private key being associated with the first device and the first identifier identifying the first device;
- a first processor that scrambles the public key using the first identifier;
- and
- a first transmitter that transmits the first identifier and the scrambled public key;
- and
- a second device comprising:
- a first transceiver that receives the first identifier and the scrambled public key;
- a second processor that unscrambles the scrambled version of the public key using the first identifier to recover the public key;
- and
- a second memory that stores the received first identifier and the public key.
A method comprising:
- using a pairing device to:
- receive a key fob identifier and a scrambled key fob public key from a key fob device, the scrambled key fob public key being scrambled based on the key fob identifier;
- unscramble the scrambled key fob public key using the key fob identifier to recover the key fob public key;
- execute a key agreement protocol authenticated by a control unit identifier associated with a control unit to generate a shared encryption key;
- encrypt the key fob public key using the shared encryption key;
- and
- transmit the encrypted key fob public key to the control unit.
Dependencies are inferred from the claim text.