On Protecting IJTAG from Data Sniffing and Alteration Attacks

Abstract

The IEEE 1687 standard (IJTAG) paves a way to the efficient access of on-chip instruments which are embedded on-chip for test, diagnosis, post-silicon debug, etc. These instruments which are provided by various untrusted third parties in the form of IPs, generally have wrapped Test Data Register (TDR). A malicious IP in the IJTAG network can sniff and possibly manipulate the data shifted in the IJTAG network and potentially expose the design/data to an untrusted entity. This paper provides a comprehensive approach to protect the test data in the IJTAG network from sniffing and alteration attack by a malicious instrument. The proposed scheme protects the test/functional data of an instrument by bypassing the shifting of test/functional data through the TDR of other instruments and hence devoid a malicious instrument the opportunity of sniffing and alteration. Also, the proposed approach keeps the basic IJTAG functionality intact. Moreover, it is highly scalable and incurs minimal area overhead as compared to the existing countermeasures. © 2022 IEEE.