In BioNanoLock, an encoded DNA sequence acts as a secret ‘biological activation-key’. This key is molecularly recognized as a unique and secret pattern of key-gates (called biological key-gates) or activates them.
This, in turn, enables the CMOS-based key-gates in the logic-locked circuit with the appropriate key value. Different voltage-levels in the multi-valued logic define the “on” or “off” state of the key-gates, thereby adding another level of ambiguity for an attacker and making it harder for the attacker to unlock the circuit.