SRAM Imprinting for System Protection and Differentiation

The foundation of trusted computation depends on the ability to verify the authenticity of the underlying hardware. This need is further compounded by the presence of counterfeit components in the market, highlighting the necessity for pre-deployment and run-time chip identification techniques. Current solutions involve burning authentication information in physical fuses or creating a unique mask for each integrated circuit, which are either costly or susceptible to forgery. While many solutions have been proposed to prevent chip counterfeiting at design time, no accurate, reference-free, and cost-effective solutions exist for chip buyers to authenticate their purchases in the pre-deployment phase and enable software-level verification at runtime. The lack of industrystandard authentication methods forces chip buyers to either adopt expensive solutions, such as X-Ray imaging, or simply rely on blind faith.

This paper presents SKU-RAM, a technique for chip identification that allows manufacturers to embed their signature into integrated circuits, provides per-device identification, and facilitates hardwareenforced time-limited licensing functionality. Our approach takes advantage of the aging-induced power-on state changes in SRAM to encode authentication data into an already fabricated device, without modifying the mask of the chips. This hardware-overheadfree augmentation to the chips eliminates numerous instances of chip counterfeiting and enables software-level authentication. We demonstrate the effectiveness of SKU-RAM as a comprehensive and scalable anti-counterfeiting solution for existing and future computing devices using commercial off-the-shelf microcontrollers and microprocessors and multi-year real-time experiments.