Method, device, and system for secure motor vehicle remote keyless entry
First Claim
1. A secure method for sending an encrypted command from a remote keyless entry device to a receiver in a motor vehicle comprising the steps of:
- defining a key generating key within the remote keyless entry device;
generating a working key from the key generating key;
transmitting the working key from the remote keyless entry device to the receiver during a training session without transmitting the key generating key; and
transmitting a message encrypted with the working key from the remote keyless entry device to the receiver.
13 Assignments
0 Petitions
Accused Products
Abstract
Methods and apparatus are provided for sending an encrypted command message from a remote keyless entry device to a receiver in a motor vehicle. The method comprises defining a key generating key within the remote keyless entry device, and using that key generating key to generate a working key. The working key is transmitted from the remote keyless entry device to the receiver during a training session without transmitting the key generating key. The working key is modified each time the remote keyless entry device is placed in the training mode. After the training session, a message encrypted with the working key can be transmitted from the remote keyless entry device to the motor vehicle receiver where the encrypted message is decrypted with the working key.
32 Citations
22 Claims
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1. A secure method for sending an encrypted command from a remote keyless entry device to a receiver in a motor vehicle comprising the steps of:
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defining a key generating key within the remote keyless entry device;
generating a working key from the key generating key;
transmitting the working key from the remote keyless entry device to the receiver during a training session without transmitting the key generating key; and
transmitting a message encrypted with the working key from the remote keyless entry device to the receiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A secure remote keyless entry system for a motor vehicle comprising:
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a remote keyless entry device comprising a key generating encryption key configured to generate a working key and a transmitter configured to transmit a ciphertext command encrypted with the working key without transmitting the key generating key; and
a receiver positioned in the motor vehicle and configured to receive and decrypt the ciphertext command encrypted with the working key. - View Dependent Claims (11, 12, 13)
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14. A remote keyless entry device for a motor vehicle comprising:
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a key generating key stored in and never transmitted from the remote keyless entry device;
a non volatile counter configured to provide an incrementable output;
an encryption circuit coupled to receive the key generating key and the output of the non volatile counter and configured to generate a working key; and
a transmitter configured to send a command message encrypted with the working key. - View Dependent Claims (15, 16)
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17. A method for sending an encrypted command from a remote keyless entry device comprising a key generating key that is never transmitted from the remote keyless entry device, an incrementable first counter, encryption circuitry, a second incrementable counter, a device identifier, a plurality of command selections, and a transmitter to a receiver in a motor vehicle comprising decryption circuitry and an incrementable third counter, the method comprising the steps of:
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generating a working key from the key generating key and an output of the incrementable first counter using an encryption algorithm;
transmitting the working key from the remote keyless entry device to the receiver during a training session;
transmitting a command message to the receiver, the command message comprising an output of the second incrementable counter, the device identifier, and one of the plurality of command selections at least a portion of which are encrypted by the encryption circuitry using the working key;
receiving the command message at the receiver;
decrypting the command message by the decryption circuitry using the working key; and
verifying the validity of the command message using an output of the incrementable third counter. - View Dependent Claims (18, 19, 20)
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21. A rolling code remote keyless entry system for a motor vehicle comprising:
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a remote keyless entry transmitter;
a key generating key in the remote keyless entry transmitter, the key generating key never transmitted from the remote keyless entry transmitter;
an incrementable counter in the remote keyless entry transmitter having an output; and
a mechanism in the remote keyless entry transmitter for generating a working key from the key generating key and the output.
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22. A rolling code remote keyless entry system for a motor vehicle comprising:
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a key generating key provided in a remote keyless entry device and never transmitted from the remote keyless entry device;
a number generator configured to generate a number for use as a working key, the number comprising a number selected from the group consisting of random numbers and pseudorandom numbers and based on the key generating key;
a transmitter configured to transmit the working key to a motor vehicle during a training session.
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Specification