Secure and Efficient Sharing of On-Chip Resources
Joel Åhlund, Markus Törmänen, Erik Larsson · 2025
Semiconductors use on-chip components, referred to as instruments, for test, debugging, firmware programming, configuration and other important functions. The instruments are needed to ensure proper device operation, however, they may be exploited by an adversary in an attack. Many different actors are involved in semiconductor development and manufacturing, this makes it important to restrict access to instruments which should not be available for all users.In this paper, we propose an authenticated instrument sharing scheme, which makes instruments available for some users while remaining hidden and inaccessible for others. Also protecting users against inside threats, like hardware trojans, in third party instruments in the device. The scheme is implemented for instrument access within an IEEE Std. 1687 (IJTAG) network, which is a frequently used standard for on-chip instrument access and integration. When deployed, our solution is (1) secure, as users are only able to access instruments they are authorized to use, other instruments remain hidden, and (2) efficient, as all of the user’s instruments will be directly accessible through the IJTAG network, after a one-step authentication process, with no additional access time overhead. We demonstrate our solution with a use case.