TriLock: IC Protection with Tunable Corruptibility and Resilience to SAT and Removal Attacks

Fun-SAT: Functional Corruptibility-Guided SAT-Based Attack on Sequential Logic Encryption

The SAT attack has shown to be efficient against most combinational logic encryption methods. It can be extended to attack sequential logic encryption techniques by leveraging circuit unrolling and model checking methods. However, with no guidance on the number of times that a circuit needs to be unrolled to find the correct key, the attack tends to solve many time-consuming Boolean satisfiability (SAT) and model checking problems, which can significantly hamper its efficiency. In this paper, we introduce Fun-SAT, a functional corruptibility-guided SAT-based attack that can significantly decre…

SANSCrypt: A Sporadic-Authentication-Based Sequential Logic Encryption Scheme

We propose SANSCrypt, a novel sequential logic encryption scheme to protect integrated circuits against reverse engineering. Previous sequential encryption methods focus on modifying the circuit state machine such that the correct functionality can be accessed by applying the correct key sequence only once. Considering the risk associated with one-time authentication, SANSCrypt adopts a new temporal dimension to logic encryption, by requiring the user to sporadically perform multiple authentications according to a protocol based on pseudo-random number generation. Analysis and validation resul…

Generalized SAT-Attack-Resistant Logic Locking

Logic locking is used to protect integrated circuits (ICs) from piracy and counterfeiting. An encrypted IC implements the correct function only when the right key is input. Many existing logic-locking methods are subject to the powerful satisfiability (SAT)-based attack. Recently, an Anti-SAT scheme has been developed. By adopting two complementary logic blocks that consist of AND/NAND trees, it makes the number of iterations needed by the SAT attack exponential to the number of input bits. Nevertheless, the Anti-SAT scheme is vulnerable to the later AppSAT and removal attacks. This paper prop…

Encrypt Flip-Flop: A Novel Logic Encryption Technique For Sequential Circuits

Logic Encryption is one of the most popular hardware security techniques which can prevent IP piracy and illegal IC overproduction. It introduces obfuscation by inserting some extra hardware into a design to hide its functionality from unauthorized users. Correct functionality of an encrypted design depends upon the application of correct keys, shared only with the authorized users. In the recent past, extensive efforts have been devoted in extracting the secret key of an encrypted design. At the same time, several countermeasures have also been proposed by the research community to thwart dif…

利用机器学习、布尔分析与ILP破解Latch Locking（锁存器锁定）

Unraveling Latch Locking Using Machine Learning, Boolean Analysis, and ILP

针对锁存器锁定的硬件安全防护机制，提出结合深度学习、布尔分析与ILP的无预言机两阶段攻击方法，在基准电路上实现了96.9%的平均密钥准确率，可破解多数电路功能且运行时间可控。