Authentication of consumable items

摘要

This invention concerns a consumable authentication method for validating the existence of an untrusted chip. A random number is encrypted using a first key and sent to an untrusted chip. In the untrusted chip it is decrypted using a secret key and re-encrypted together with a data message read from the untrusted chip. This is decrypted so that a comparison can be with the generated random number and the read data message.