Image encryption and decryption utilizing physical unclonable function-based key generator by Ta/WTiOx/Pt memristor array

In this work, an encryption and decryption system utilizing physical unclonable function (PUF) characteristics of the Ta/WTiOx/Pt memristor array as hardware-level security primitive is demonstrated. PUF characteristics of the memristor are mainly attributed to the resistance variations, which are used as a physical unclonable entropy source with Hamming weight and inter Hamming distance close to 50%, showing high unpredictability in the application of a cryptographic key generator. Furthermore, combining international advanced encryption standard cryptographic algorithm and PUF-based keys, the encryption and decryption of 512 × 512-pixel Chinese Loong RGB image is successfully implemented by utilizing only 128 memristor arrays, which proves the lightweight and unclonable properties of the PUF-based security system. This work demonstrates that efficient image encryption and decryption can be accomplished by PUF characteristics of memristor arrays with high security and efficiency, proving its promising potential in constructing hardware–software cooperative security systems.