Patent ID: 6981142

Claim:
A method for propagating information in an electronic lock-and-key system, said method comprising: inserting an original message to be propagated to an n-th lock or key into a memory of a first key or a first lock, respectively, copying, on any use of said first key or said first lock, said original message into a memory of a second lock or key, respectively, but remains in said first key's or first lock's, respectively, memory, copying, on any subsequent use of said first and second key and said first and second lock, said original message into a memory of a next lock or key, respectively, but remains in the memories of said previously used locks and keys, respectively, propagating said original message until it reaches its destination, and producing a confirmation message in the n-th lock or key, thereby acknowledging reception of said original message which confirmation message serves to control erasing of the copies of the original message in the memories of the locks and keys.