APPLYING CIRCUIT DELAY-BASED PHYSICALLY UNCLONABLE FUNCTIONS (PUFS) FOR MASKING OPERATION OF MEMORY-BASED PUFS TO RESIST INVASIVE AND CLONE ATTACKS

One feature pertains to generating a unique identifier for an electronic device by combining static random access memory (SRAM) PUFs and circuit delay based PUFs (e.g., ring oscillator (RO) PUFs, arbiter PUFs, etc.). The circuit delay based PUFs may be used to conceal either a challenge to, and/or response from, the SRAM PUFs, thereby inhibiting an attacker from being able to clone a memory device's response.