A New Access Protocol for Elevating the Security of IJTAG Network

The modern-day SoCs have various instruments and proprietary data embedded on chip for test, diagnosis, post-silicon debug, in-field health monitoring, authentication, counterfeit detection, etc. The testing infrastructure such as IEEE Std. 1687 (IJTAG) is incorporated into the ICs for flexible access to these on-chip instruments. However, this standard can be illegitimately used by malicious users for instigating side-channel attacks. In order to improve the security of the IJTAG network, a secure access protocol based on Chip ID, access software and Locking SIB (LSIB) has been proposed. Although this protocol elevates the security of the IJTAG network, in recent works, it has been shown that the secure access protocol is vulnerable to machine learning attack and differential analysis attack. In this work, a new secure access protocol is proposed which is built over the existing secure access protocol. The proposed protocol uses multiple templates which are selected randomly for embedding the key bits. It is shown that the proposed protocol can mitigate the efficacy of machine learning attack and differential analysis attack significantly. Moreover, it is simple to implement and incurs a marginal overhead in terms of area.