Hardware IP Classification through Weighted Characteristics

Today’s business model for hardware designs frequently incorporates third-party Intellectual Property (IP) due to the many benefits it can bring to a company. For instance, outsourcing certain components of an overall design can reduce time-to-market by allowing each party to specialize and perfect a specific part of the overall design. However, allowing third-party involvement also increases the possibility of malicious attacks, such as hardware Trojan insertion. Trojan insertion is a particularly dangerous security threat because testing the functionality of an IP can often leave the Trojan undetected. Therefore, this thesis work provides an improvement on a Trojan detection method known as Structural Checking which analyzes Register-Transfer Level (RTL) and gate-level soft IPs. Given an unknown IP, the Structural Checking tool will break down the design primary ports and internal signals into assets that fall into six characteristics. These characteristics organize how the IP is structured and provide information about the unknown IP’s overall function. The tool also provides a library of known designs referred to as the Golden Reference Library (GRL). All entries in the library are also broken down into the same six characteristics and are either known to be clean or known to have a Trojan inserted. An overall percent match for each library entry against the unknown IP is calculated by first computing a percent match within each characteristic. A weighted average of these percent matches makes up the final percentage. If the library entry with the best match is known to have a Trojan inserted, then the unknown design is likely to have a Trojan as well and vice versa. Due to the structural variability of soft IP designs, it is vital to provide the best possible weighting of the six characteristics to best match the unknown IP to the most similar library entry. This thesis work provides a statistical approach to finding the best weights to optimize the Structural Checking tool’s matching algorithm

Structural Checking Tool Restructure and Matching Improvements

With the rising complexity and size of hardware designs, saving development time and cost by employing third-party intellectual property (IP) into various first-party designs has become a necessity. However, using third-party IPs introduces the risk of adding malicious behavior to the design, including hardware Trojans. Different from software Trojan detection, the detection of hardware Trojans in an efficient and cost-effective manner is an ongoing area of study and has significant complexities depending on the development stage where Trojan detection is leveraged. Therefore, this thesis research proposes improvements to various components of the soft IP analysis methodology utilized by the Structural Checking Tool. The Structural Checking Tool analyzes the register-transfer level (RTL) code of IPs to determine their functionalities and to detect and identify hardware Trojans inserted. The Structural Checking process entails parsing a design to yield a structural representation and assigning assets that encompass 12 different characteristics to the primary ports and internal signals. With coarse-grained asset reassignment based on external and internal signal connections, matching can be performed against trusted IPs to classify the functionality of an unknown soft IP. Further analysis is done using a Golden Reference Library (GRL) containing information about known Trojan-free and Trojan-infested designs and serves as a vital component for unknown soft IP comparison. Following functional identification, the unknown soft IP is run through a fine-grained reassignment strategy to ensure usage of up-to-date GRL assets, and then the matching process is used to determine whether said IP is Trojan-infested or Trojan-free. This necessitates a large GRL while maintaining a balance of computational resources and high accuracy to ensure effective matching