Digitally Assisted Mixed-Signal Circuit Security

• Published in: IEEE transactions on computer-aided design of integrated circuits and systems Vol. 41; no. 8; pp. 2449 - 2462
• Main Authors: Leonhard, Julian, Limaye, Nimisha, Turk, Shadi, Sayed, Alhassan, Rizo, Alan Rodrigo Diaz, Aboushady, Hassan, Sinanoglu, Ozgur, Stratigopoulos, Haralampos-G.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Analog to digital converters; Calibration; Circuit design; Cloning; Computer Aided Engineering; Computer Science; Cryptography and Security; Design; Engineering Sciences; Hardware; Hardware security and trust; Integrated circuits; Intellectual property; IP/IC piracy; Locking; Micro and nanotechnologies; Microelectronics; mixed-signal integrated circuits (ICs); Neural networks; Piracy; Security; Transistors
• ISSN: 0278-0070; 1937-4151
• DOI: 10.1109/TCAD.2021.3111550

The design and manufacturing steps of a chip typically involve several parties. For example, a chip may comprise several third-party intellectual property (IP) cores and the integrated circuit (IC) fabrication may be outsourced to a third-party foundry. IP cores and ICs are shared with potentially untrusted third parties and, as a result, are subject to piracy attacks. Even more, any legally purchased chip may be reverse engineered to retrieve the design down to transistor level and, thereby, it is also subject to piracy attacks. In this article, we propose MixLock , an anti-piracy countermeasure for mixed-signal IP cores and ICs. MixLock protection is based on inserting a lock mechanism into the design such that correct functionality is established only after applying a key which is the designer's secret. The lock mechanism acts on the mixed-signal performances by leveraging logic locking of the digital part. MixLock presents several key attributes. It is generally applicable, it is nonintrusive to the sensitive analog section, it incurs no performance penalty and has very low area and power overheads, it is fully automated, and it is capable of co-optimizing security in both the analog and digital domains. We demonstrate MixLock on a <inline-formula> <tex-math notation="LaTeX">\Sigma \Delta </tex-math></inline-formula> analog-to-digital converter (ADC) using hardware measurements and an audio demonstrator.