6.3.18 Authentication Attempts Counters (AAC)

Each of the four AAC fields contains an 8-bit attempts counter for the authentication process. Each AAC field corresponds to an authentication key set. The attempts counter limits the number of consecutive incorrect attempts to authenticate to four, after which it locks the authentication key set from future use. The AAC will decrement ($FF, $EE, $CC, $88, $00) with each incorrect attempt to authenticate. The AAC permanently locks the corresponding key set once its value reaches $00. Prior to reaching $00, any correct attempt to authenticate resets the AAC value to $FF.