Breaking Analog Biasing Locking Techniques via Re-Synthesis

Leonhard, Julian; Elshamy, Mohamed; Louërat, Marie-Minerve; Stratigopoulos, Haralampos-G.

doi:10.1145/3394885.3431603

Cited by 8 publications

(14 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The majority of them target biasing locking [17]- [20]. The counter-attack in [17] is demonstrated to break all existing biasing locking techniques.…”

Section: B Counter-attacks On Lockingmentioning

confidence: 99%

“…Recommendations are also given on how to mitigate these two counter-attacks. The counter-attacks in [19], [20] are the most powerful since they are generally applicable to any biasing locking scheme, they cannot be mitigated, and also, compared to [17] where the attacker must derive circuit equations, are easier to execute even by a weak attacker with no particular circuit design expertise. The underlying idea is to remove the locked biasing circuit and replace it with an unlocked version of it and, thereafter, use optimization to synthesize the biasing circuit together with the circuit core.…”

Section: B Counter-attacks On Lockingmentioning

confidence: 99%

“…They differ in the way the fitness function is defined. In [19], the optimization aims at matching the frequency or transient response to that of the oracle, whereas in [20] the optimization aims at satisfying the performance tradeoff promised in the datasheet without requiring an oracle. In [19], a second optimization is performed aiming at recovering the secret key by using the extracted obfuscated component value as a second fitness criterion.…”

Section: B Counter-attacks On Lockingmentioning

confidence: 99%

“…20 , thus the nominal key width of 128 bit is reduced to 108 effective bits, still a very strong analog security level.Table I also provides the security metrics for the MixLock 1.0 implementation that employs SFLL. By construction of the SFLL lock mechanism, for any incorrect key having HD > 1 from the correct key, every query of the circuit with the same input waveform leads to the same errors and, thereby, the SNR performance degrades by the same amount.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Digitally Assisted Mixed-Signal Circuit Security

Leonhard¹,

Limaye

Turk

et al. 2022

IEEE Trans. Comput.-Aided Des. Integr. Circuits Syst.

Self Cite

View full text Add to dashboard Cite

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 transistorlevel and, thereby, it is also subject to piracy attacks. In this paper, 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 mixedsignal performances by leveraging logic locking of the digital part. MixLock presents several key attributes. It is generally applicable, it is non-intrusive 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 Σ∆ Analog-to-Digital Converter (ADC) using hardware measurements and an audio demonstrator.

show abstract

“…The majority of them target biasing locking [17]- [20]. The counter-attack in [17] is demonstrated to break all existing biasing locking techniques.…”

Section: B Counter-attacks On Lockingmentioning

confidence: 99%

Section: B Counter-attacks On Lockingmentioning

confidence: 99%

Section: B Counter-attacks On Lockingmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Digitally Assisted Mixed-Signal Circuit Security

Leonhard¹,

Limaye

Turk

et al. 2022

IEEE Trans. Comput.-Aided Des. Integr. Circuits Syst.

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand, counter-attacks were proposed recently that break biasing locking allowing the attacker to recover the secret key or to remove the lock by re-synthesizing the biasing circuit [32]- [35].…”

Section: Prior Art In Locking Ams Icsmentioning

confidence: 99%

Locking by Untuning: A Lock-Less Approach for Analog and Mixed-Signal IC Security

Elshamy

Sayed

Louërat

et al. 2021

IEEE Trans. VLSI Syst.

Self Cite

View full text Add to dashboard Cite

We propose an anti-piracy security approach for programmable analog and mixed-signal (AMS) Integrated Circuits (ICs). The security approach relies on functionality locking by leveraging the inherent programmability and utilizing the configuration settings as secret keys or, equivalently, the programming bits as key-bits. When invalid keys are applied, the circuit is untuned and, as a result, its functionality breaks, i.e., at least one of the performances violates its specification. As long as the calibration algorithm that produces the configuration settings can be kept secret, the proposed approach can serve as a countermeasure against all types of counterfeiting, i.e., cloning, overbuilding, remarking, and recycling. An important advantage of the proposed approach is that it is lock-less. It leaves the design intact, there is no change to the design flow, and there is no performance penalty and no area or power overheads due to the lock operation. We demonstrate it on a Σ∆ Analogto-Digital Converter (ADC) with 194-bit programmability and complex calibration algorithm used in the context of highlydigitized, multi-standard RF receivers.

show abstract

Utilizing layout effects for analog logic locking

Aljafar,

Azais,

Flottes

et al. 2024

J Cryptogr Eng

View full text Add to dashboard Cite

While numerous obfuscation techniques are available for securing digital assets in the digital domain, there has been a notable lack of focus on protecting intellectual property (IP) in the analog domain. This is primarily due to the relatively smaller footprint of analog components within an integrated circuit (IC), with the majority of the surface dedicated to digital elements. However, despite their smaller nature, analog components are highly valuable IP and warrant effective protection. In this paper, we present a groundbreaking method for safeguarding analog IP by harnessing layout-based effects that are typically considered undesirable in IC design. Specifically, we exploit the impact of length of oxide diffusion and well proximity effect on transistors to fine-tune critical parameters such as transconductance ($$g_{m}$$ g m ) and threshold voltage ($$V_{th}$$ V th ). These parameters remain concealed behind key inputs, akin to the logic locking approach employed in digital ICs. Our research explores the application of layout-based effects in two commercial CMOS technologies, namely a 28 nm and a 65 nm node. To demonstrate the efficacy of our proposed technique, we implement it for locking an operational transconductance amplifier. Extensive simulations are performed, evaluating the obfuscation strength by applying a large number of key sets (over 50,000 and 300,000). The results exhibit a significant degradation in performance metrics, such as open-loop gain (up to 130 dB), phase margin (up to 50$$^\circ $$ ∘ ), 3 dB bandwidth (approximately 2.5 MHz), and power consumption (around 1 mW) when incorrect keys are employed. Our findings highlight the advantages of our approach as well as the associated overhead.

show abstract

Breaking Analog Biasing Locking Techniques via Re-Synthesis

Cited by 8 publications

References 20 publications

Digitally Assisted Mixed-Signal Circuit Security

Digitally Assisted Mixed-Signal Circuit Security

Locking by Untuning: A Lock-Less Approach for Analog and Mixed-Signal IC Security

Utilizing layout effects for analog logic locking

Contact Info

Product

Resources

About