Echeloned IJTAG data protection

This paper presents a novel IJTAG-based data protection method that utilizes stream ciphers and IJTAG topology. The method protects IJTAG data with encryption. It further imposes access restriction on user control sequencing. In particular, it complements IJTAG encryption-based data access with IJTAG topology, and it augments IJTAG-based authorization checks to defend against unauthorized and unintended access. It also allows the device owner to implement use case isolation for better compartmentalization of the supply chain.