Patent ID: 7805612
Filing Date: 2010-09-28
Classification: H04L

Abstract:
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.