Patent ID: 8781442

Claim:
A method for one-way authentication of a first communication device with a second communication device comprising: a. receiving at the first communication device a real-time time based value from a device remote from the first and second communication devices; b. combining into a composite message the time based value and message content; c. applying a cryptographic algorithm to the composite message to produce a message signature of the message content and the time based value; d. transmitting the message content, the time based value, and the message signature with the first communication device; wherein the time based value indicates an approximate time the first communication device transmits the message content and also ensures that the message signature is unique for separate transmissions of the same message content; wherein the cryptographic algorithm is one of a Message-Digest 5 (MD5) algorithm, a secure hash algorithm (SHA), a RACE Integrity Primitives Evaluation Message Digest (RIPEMD) algorithm, Cellular Authentication, Voice Privacy and Encryption (CAVE) algorithm, or a Whirlpool algorithm; and wherein the time based value is to be used by the second communication device for determining whether the time-based value precedes a current time of the second communication device more than a predetermined increment of time and wherein the second communication device is intended to discard the received message if the first communication device transmitted the message more than the predetermined increment of time before the current time of the second communication device.