Securing Heterogeneous 2.5D ICs Against IP Theft through Dynamic Interposer Obfuscation

Recent breakthroughs in heterogeneous integration (HI) technologies using 2.5D and 3D ICs have been key to advances in the semiconductor industry. However, heterogeneous integration has also led to several sources of distrust due to the use of third-party IP, testing, and fabrication facilities in the design and manufacturing process. Recent work on 2.5D IC security has only focused on attacks that can be mounted through rogue chiplets integrated in the design. Thus, existing solutions implement inter-chiplet communication protocols that prevent unauthorized data modification and interruption in a 2.5D system. However, none of the existing solutions offer inherent security against IP theft. We develop a comprehensive threat model for 2.5D systems indicating that such systems remain vulnerable to IP theft. We present a method that prevents IP theft by obfuscating the connectivity of chiplets on the interposer using reconfigurable interconnection networks. We also evaluate the PPA impact and security offered by our proposed scheme.