Authentication Algorithm for the Universal Authenticated Item Monitoring System (AIMS)

The authentication algorithm for the AIMS system [1] provides for a method of insuring transmitted data validity. An AIMS sensor transmitter (ASTX) and Receiver Processing Unit (RPU) contain unique and identical thirty-two byte authentication keys. The ASTX's use the authentication algorithm to generate unique authentication bytes that represent the resultant processing of the authentication algorithm. Each message contains the transmitted data with the authentication bytes appended to it. Algorithm processing depends upon internal ASTX counters, identification bytes, data, and the authentication key. Using the data transmitted, an RPU can compute a result and compare it with the transmitted authentication bytes. Comparison of data generates a result determining validity of data. The data entering the algorithm represents a very large range of numbers, which provides a greater level of difficulty for prediction of future results. Structure of the algorithm provides a method to alter the format of messages, which allows for integration into systems other than AIMS with the same effectiveness.