Polygon Boolean operations and physical unclonable functions implemented by an Ag-embedded sodium-alginate-based memristor for image encryption/decryption.

This article focuses on the development and characterization of an Au/sodium alginate (SA): silver nanoparticles (Ag NPs)/indium tin oxide (ITO) memristor that exhibits coexisting nonvolatile memory (NVM) and volatile threshold switching (VTS) behaviors controlled by compliance current in current pulse mode. The device demonstrates stable NVM at higher compliance currents and VTS at lower currents, with random switching behavior at intermediate currents, enabling the implementation of four polygon Boolean logic operations (AND, OR, NOT, XOR) and physical unclonable functions (PUFs) with an inter-class Hamming distance of 50.75%. Utilizing PUF-generated keys, the memristor array performs in situ image encryption and decryption via XOR logic, highlighting its potential for secure hardware applications by combining in-memory computing and intrinsic hardware security features. The study also addresses challenges of voltage-induced current overshoot by employing current pulse mode to improve switching stability and endurance.