Patent ID: 8194550

Claim:
A method for determining whether information received from a vehicle is reliable in a vehicle-to-vehicle communications system, said method comprising: receiving a message from a suspect vehicle by a subject vehicle; determining whether there is a memory bucket stored on the subject vehicle for the suspect vehicle; creating a memory bucket for the suspect vehicle if a memory bucket for the suspect vehicle does not exist on the subject vehicle; transmitting a challenge question from the subject vehicle to the suspect vehicle to determine whether the suspect vehicle is reliable; increasing a number of tokens in the bucket for the suspect vehicle if the suspect vehicle responds to the challenge question with a correct answer; decreasing the number of tokens in the token bucket for the suspect vehicle if the response to the challenge question is incorrect; accepting the message from the suspect vehicle if a number of tokens in the bucket for the suspect vehicle is greater than a predetermined upper threshold; and discarding the message from the suspect vehicle if the number of tokens in the bucket for the suspect vehicle is less than a predetermined lower threshold.