Patent ID: 7975142

Claim:
A ring authentication method for a concurrency environment, the method comprising: providing a plurality of user devices {P 1 , . . . , P n } including a sender and a receiver, wherein each of the user devices {P 1 , . . . , P n } sends and receives a message with another one of the user devices {P 1 , . . . , P n } to provide sender anonymity; sending a message from the sender to the receiver; requesting the sender to certify the message, the requesting being performed by the receiver; sending a message certification value certifying that the sender is one of the plurality of user devices {P 1 , . . . , P n } and authenticating the message by using a signature of proof of knowledge from the sender to the receiver; and verifying the message certification value from the sender and checking whether the message is authenticated, the verifying and checking being performed by the receiver.