Due to the evolution in the Integrated Circuit (IC) supply chain, soft/firm/hard cores involved in a system under development and manufactured ICs come from numerous, and possibly unreliable, sources. This loss of control over the entire design/production flow leads to several threats including the insertion by an attacker of malicious circuitries known as Hardware Trojans. Hardware Trojan insertion modifies the functionality of the circuit, possibly its reliability, in order to alter its behavior, generate a denial of service or leak secret information for instance. Numerous methods have been proposed in the literature to detect the presence of such alterations, or prevent their insertion. This paper focuses on methods based on logic testing. Researches in this domain are surveyed and remaining unresolved challenges are described along with proposals to meet these challenges.

International audienceHardware Trojan Horses (HTHs) are malicious and stealthy alterations of integrated circuits introduced at design or fabrication steps in order to modify the circuit's intended behavior when deployed in the field. Due to HTHs stealth and diversity (intended alteration, implementation, triggering conditions), detecting and/or locating them is a challenging task. Several HTHs detection approaches have been proposed to address this problem. This paper focuses on so-called "side-channel analysis" methods, i.e., methods that use power or delay measurements to detect potential HTHs. It reviews these methods and raises some considerations about the experiments made to evaluate them. Moreover, an original case study is presented in which we show that weak experiments may lead to misleading interpretations. Last, we evoke problems inherent to actual power and delay measurements

A digital finite impulse response (FIR) filter is a ubiquitous block in digital signal processing applications and its behavior is determined by its coefficients. To protect filter coefficients from an adversary, efficient obfuscation techniques have been proposed, either by hiding them behind decoys or replacing them by key bits. In this article, we initially introduce a query attack that can discover the secret key of such obfuscated FIR filters, which could not be broken by the existing prominent attacks. Then, we propose a first of its kind hybrid technique, including both hardware obfuscation and logic locking using a point function for the protection of parallel direct and transposed forms of digital FIR filters. Experimental results show that the hybrid protection technique can lead to FIR filters with higher security while maintaining the hardware complexity competitive or superior to those locked by prominent logic locking methods. It is also shown that the protected multiplier blocks and FIR filters are resilient to existing attacks. The results on different forms and realizations of FIR filters show that the parallel direct form FIR filter has a promising potential for a secure design.

The current trend to globalize the supply chain in the Integrated Circuits (ICs) industry has raised several security concerns including, among others, IC overproduction. Over the past years, logic locking has grown into a prominent countermeasure to tackle this threat in particular. Logic locking consists of “locking” an IC with an added primary input, the so-called key, which, unless fed with the correct secret value, renders the ICs unusable. One of the first criteria ensuring the quality of a logic locking technique was the output corruption, i.e., the corruption at the outputs of a locked circuit, for any wrong key value. However, since the introduction of SAT-based attacks, resulting countermeasures have compromised this criterion in favor of a better resilience against such attacks. In this work, we propose SKG-Lock+, a Provably Secure Logic Locking scheme that can thwart SAT-based attacks while maintaining significant output corruption. We perform a comprehensive security analysis of SKG-Lock+ and show its resilience against SAT-based attacks, as well as various other state-of-the-art attacks. Compared with related works, SKG-Lock+ provides higher output corruption and incurs acceptable overhead.