Patent ID: 7529939

Claim:
A method of securely transferring data from an encoder to a decoder, said encoder including an encoder timer and said decoder including a decoder timer, said method including the steps of: (a) during a learning process receiving a value of said encoder timer at said decoder and determining a mathematical difference value between said value of said encoder timer and a value of said decoder timer; (b) storing said mathematical difference value as a timer relationship value in said decoder; (c) at the encoder encrypting a data word to form a transmission word, said data word including information identifying a present value of said encoder timer; (d) transmitting the transmission word to the decoder; (e) at the decoder decrypting the transmission word; and (f) determining a mathematical difference value between said present encoder timer value and a present decoder timer value; and g) validating the transmission word by comparing the mathematical difference value between said present encoder timer value and said present decoder timer value with said timer relationship value stored in said decoder.