What characteristic differentiates duress codes from user codes?

Duress codes are specifically designed as a covert method for a user to signal distress while simultaneously appearing to enter their regular user code. This critical functionality sets duress codes apart from standard user codes, which simply grant access to a system without any embedded layers of meaning beyond authentication. The distinction lies in the intent and use: duress codes serve a dual purpose—allowing continued access while also alerting security personnel to the user's need for help, effectively differentiating them not only in function but in necessity and implementation within security systems.

Understanding this difference is crucial, particularly in environments where user safety may be at risk, highlighting the importance of incorporating such measures into intrusion detection systems. While user codes may suffice for general authentication, duress codes represent a proactive security measure responding to potential threats.