Secure and scalable access protocol for enhancing IEEE 1687 network security

Abstract Modern System-on-Chip (SoC) designs integrate various embedded instruments and proprietary data to support critical operations such as testing, diagnosis, and in-field health monitoring. The IEEE Std. 1687 (IJTAG) is widely adopted to provide efficient and flexible access to these on-chip instruments. However, its reconfigurable nature exposes a significant attack surface, making it vulnerable to advanced security threats, including machine learning, differential analysis, and power analysis attacks, which can extract Chip IDs and cryptographic keys. To enhance the security of the IJTAG architecture, a secure access protocol has been proposed in the literature. In this secure access scheme, a random number generator produces a bitstream, and whenever a predefined template matches, a key bit is inserted into the bitstream; this process continues until all key bits are embedded. However, the reliance on a single static template renders the scheme predictable and susceptible to key recovery. To overcome this limitation, we propose a multi-dynamic template based secure access protocol , where multip