Cryptographic Key Generation and In Situ Encryption in One‐Transistor‐One‐Resistor Memristors for Hardware Security

Abstract The problem of hardware security is exacerbating in the artificial intelligence & Internet of Things era. Physical unclonable function (PUF) is a promising security primitive that exploits the intrinsic random variations in electronic hardware to produce digital keys. Here, it is shown for the first time that the subthreshold slope (S.S) variations of the transistors can be utilized as the entropy source of the PUF to generate the physical keys. By combining this S.S PUF with a memristor‐based XOR logic function, an in situ encryption/decryption scheme is proposed in a compact one‐transistor‐one‐resistor (1T1R) architecture. It is experimentally demonstrated that the S.S PUF shows great reproducibility, uniqueness, and uniformity. Using the S.S PUF keys, encryption and decryption are successfully implemented for three 16‐bit binary sequences in 1T1R devices. The results demonstrate that the unique features of 1T1R can enlighten functional design at the device level against hardware security threats, and the security, memory, and computing can be realized on the same device.