Hybrid Obfuscation of Chiplet-Based Systems

The growing concern about offshore chip manufacturing has created considerable interest in solutions that can ensure the integrity and security of chips. Among various solutions, split manufacturing has received a lot of attention due to its security guarantees. With the recent emergence of new heterogeneous manufacturing technologies, including chiplet-based systems, there is a new opportunity for revisiting the design considerations for split manufacturing to fully exploit the opportunities presented by chiplet-based systems and improve various metrics, such as security, performance, and overhead.This work improves the state-of-the-art in secure chip manufacturing by proposing a new split manufacturing scheme. The key idea is to exploit the capabilities provided by chiplet integration technology for designing a new hybrid split manufacturing scheme that includes both vertical and horizontal splitting. Unlike existing vertical-only split manufacturing mechanisms, that target obfuscation of interconnections by splitting the design at a specific metallization layer into two portions, the proposed hybrid method increases trust by exploiting the chiplet paradigm shift, specifically, breaking the design into sub-designs, each represented by chiplets (independently fabricated), and obfuscating interconnections among them. The proposed obfuscation mechanism targets systems that exploit the chiplet technology to obtain important performance advantages, thus any chiplet-related overhead is not due to obfuscation. We evaluate our method using several experiments and compare it with the state-of-the-art using standard metrics, including area, power, delay, wirelength, and trust. Compared to conventional split manufacturing, our hybrid method achieves up to 245× higher trust, while exhibiting negligible overhead.