Mutual authentication is used when both parties need to authenticate prior to a transaction. The ATAES132 is designed with a set of high reliability secure counters. These can be used to track events in applications where it is essential to know how many times an event has occurred. Nobody can change, reset or reverse the values of these counters without a successful authentication. Optionally, the requirement to authenticate can also apply for incrementing the counters. The ATAES132 holds a wide range of key management commands. Commands like key create, import, export, and transfer have not been available in earlier authentication devices. One can upgrade or revocate compromised keys, or periodically change keys, in the field without having to remove or replace the EEPROM. Even in these situations, authentication keys will never be exposed. One implication of the choice of crypto algorithms is that many legacy systems with a software implementation of AES can easily upgrade to ATAES132’s hardware implementation and thus strengthen the security of the system.