Spintronics-based 'logic locks' to boost chip security

Next-generation electronic devices could feature enhanced security systems built into their circuitry to help fend off malicious attacks. Protective ‘logic locks’ — based on an advanced branch of electronics called spintronics — could be incorporated into the integrated circuits of electronic chips to defend chip security, according to research from the King Abdullah University of Science and Technology (KAUST). Yehia Massoud, a researcher from KAUST, said the need for hardware-based security features reflects the globalised nature of modern electronics manufacturing.

Electronics companies usually employ large, specialised, external foundries to produce their chips, which reduces costs but introduces potential vulnerabilities to the supply chain. The circuit design could be illegally copied by an untrusted foundry for counterfeit chip production or could be maliciously modified by the incorporation of ‘hardware Trojans’ into the circuitry that detrimentally affects its behaviour in some way.

Divyanshu Divyanshu, a PhD student in Massoud’s lab, said security approaches like logic locking are widely used to increase confidence in the globalised integrated circuit manufacturing chain. To defend chip security, the ITL team designed an integrated circuit logic lock based on a component called a magnetic tunnel junction (MTJ). Logic locking works like a combination lock; unless the correct ‘key’ combination signal is supplied to the lock, the circuit’s operation is scrambled. “The keys to the lock are stored in tamper-proof memory, ensuring hardware security against several threat models,” Divyanshu said.

The logic-locking behaviour of the MTJ is based on spintronics, an emerging form of advanced electronics. “Spintronics is a field of study in which a physical property of electrons called spin is exploited, in addition to their charge,” Massoud said.

The MTJ’s electronic output depends on the spin alignment of the electrons within it; only when the MTJ receives the correct key signal input does it produce the correct output for the protected circuit to function. Spin-based devices have several advantages compared to conventional silicon components, including low operational voltage and no power consumption during standby. “With the advancement in fabrication methods, the possibility of using emerging spintronic device structures in the chip design has increased. These properties make spintronic devices a potential choice for exploring hardware security,” Massoud said.

Research has shown that spintronics could be suitable for the logic-locking task; the researchers aim to include the investigation of other spin-based devices to develop logic-locking blocks, with the help of the fabrication facilities available at KAUST. The research findings were published in IEEE Access.

Image credit: iStock.com/matejmo