The working Mechanism
With DS28CN01, the MAC computation incorporates a random challenge chosen by the MAC recipient. Figure 1 illustrates the general concept. The longer the challenge, the more difficult it is to record all possible responses for a potential replay.
Figure 1. The challenge-and-response authentication process proves the authenticity of a MAC originator.
To prove the authenticity of the MAC originator, the MAC recipient generates a random number and sends it as a challenge to the originator. The MAC originator must then compute a new MAC based on the secret key, the message, and the recipient's challenge. The originator then sends the computed result back to the recipient. If the originator proves capable of generating a valid MAC for any challenge, it is very certain that it knows the secret and, therefore, can be considered authentic. The technical term for this process is challenge-and-response authentication.
Typical Operating Circuit
|DS28CN01EVKIT||Evaluation Board/Evaluation System for the DS28CN01|
|DSAUTHSK||Evaluation Kit for the DS28E01-100, DS28CN01, and DS2460|