Use of global clock to secure and synchronize messages in XM and SMS messages to a vehicle
First Claim
1. A method for providing security for a communications signal transmitted from a server to a vehicle, said method comprising:
- periodically receiving a global time signal by the vehicle and the server;
synchronizing a local time signal in the vehicle and the server to the global time signal;
adding a server local time signal to a one-way message including a vehicle identification number and a function code in the server;
encrypting the message in the server;
transmitting the message from the server to the vehicle;
receiving the message in the vehicle;
decrypting the message in the vehicle;
comparing a vehicle identification number of the vehicle with the vehicle identification number in the message;
comparing the server local time signal in the message with a vehicle local time signal in the vehicle; and
performing a function associated with the function code if the vehicle identification numbers match and the server local time signal in the message is within a predefined window of the vehicle local time signal.
12 Assignments
0 Petitions
Accused Products
Abstract
A system and method for providing secure one-way transmissions in a vehicle wireless communications system. The system and method rely on a clock signal to assure that the vehicle and server receive proper messages. The vehicle and the server will periodically synchronize their internal clocks to a global clock signal. The server will add its local time to the body of a message including a vehicle identification number and a function code. The server will then encrypt the message and transmit it to the vehicle. The vehicle will decrypt the message and compare the transmitted vehicle identification number with its identification number. If the identification numbers match, the vehicle will then see if the time in the message is within a predefined window of the vehicle time. If the transmitted time is within the predefined window of the vehicle time, the vehicle will accept the message and perform the function.
12 Citations
20 Claims
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1. A method for providing security for a communications signal transmitted from a server to a vehicle, said method comprising:
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periodically receiving a global time signal by the vehicle and the server; synchronizing a local time signal in the vehicle and the server to the global time signal; adding a server local time signal to a one-way message including a vehicle identification number and a function code in the server; encrypting the message in the server; transmitting the message from the server to the vehicle; receiving the message in the vehicle; decrypting the message in the vehicle; comparing a vehicle identification number of the vehicle with the vehicle identification number in the message; comparing the server local time signal in the message with a vehicle local time signal in the vehicle; and performing a function associated with the function code if the vehicle identification numbers match and the server local time signal in the message is within a predefined window of the vehicle local time signal. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for providing security for a short message communications signal transmitted between a server and a vehicle, said method comprising:
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periodically receiving a global time signal by the vehicle and the server; synchronizing a local time signal in the vehicle and the server to the global time signal; adding the local time signal to a one-way message including a vehicle identification number and a function code in the server; transmitting the message between the server and the vehicle; receiving the message by the vehicle or the server; comparing the local time signal in the message with the local time signal in the vehicle or the server that received the message; and performing a function associated with the function code if the local time signal in the message is within a predefined window of the local time signal in the vehicle or the server. - View Dependent Claims (8, 9, 10)
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11. A system for providing security for a communications signal transmitted from a server to a vehicle, said system comprising:
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means for periodically receiving a global time signal by the vehicle and the server; means for synchronizing a local time signal in the vehicle and the server to the global time signal; means for adding a server local time signal to a one-way message including a vehicle identification number and a function code in the server; means for encrypting the message in the server; means for transmitting the message from the server to the vehicle; means for receiving the message in the vehicle; means for decrypting the message in the vehicle; means for comparing a vehicle identification number of the vehicle with the vehicle identification number in the message; means for comparing the server local time signal in the message with a vehicle local time signal in the vehicle; and means for performing a function associated with the function code if the vehicle identification numbers match and the server local time signal in the message is within a predefined window of the vehicle local time signal. - View Dependent Claims (12, 13, 14, 15)
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16. A wireless vehicle communication system comprising:
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a vehicle receiving a global time signal, said vehicle synchronizing a vehicle local time signal to the global time signal; and a server receiving the global time signal, said server synchronizing a server local time signal to the global time signal, said server or the vehicle adding the server or vehicle local time signal to a one-way message including a vehicle identification number and a function code, said server or vehicle transmitting the message, said vehicle or server comparing the local time signal in the message with the local time signal in the server or the vehicle that receives the message and said vehicle or server performing a function associated with the function code if the local time signal in the message is within a predefined window of the local time signal in the server or the vehicle. - View Dependent Claims (17, 18, 19, 20)
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Specification