Sweep to the Secret: A Constant Propagation Attack on Logic Locking
Abdulrahman Alaql, Domenic J. Forte, Swarup Bhunia · 2019
The development of hardware intellectual properties (IPs) has faced many challenges due to malicious modifications and piracy. One potential solution to protect IPs against these attacks is to perform a key-based logic locking process that disables the functionality and corrupts the output of the IP when the incorrect key value is applied. However, many attacks on logic locking have been introduced to break the locking mechanism and obtain the key. In this paper, we present SWEEP, a constant propagation attack that exploits the change in characteristics of the IP when a single key-bit value is hard-coded. The attack process starts with analyzing design features that are generated from the synthesis tool and establishes a correlation between these features and the correct key values. In order to perform the attack, the logic locking tool needs to be available. The level of accuracy of the extracted key mainly depends on the type of logic locking approach used to obfuscate the IP. Our attack was applied to ISCAS85, and MCNC benchmarks obfuscated using various logic locking techniques and has obtained an average accuracy of 92.09%.