Identification of IP control units by state encoding and side channel verification.

Synchronous finite state machines (FSMs) are the backbone of an embedded controller design. We propose a non-destructive watermark embedding algorithm and a contactless verification method for protecting the design intellectual property (IP) of an embedded controller modeled as a synchronous FSM. The proposed embedding algorithm does not require adding redundant data such as non-functional states or state transitions. The verification scheme does not require accessing internal states, either. The central ideas are based on embedding and verifying an IP designer's watermark at a FSM-level, as opposed to a state level. The embedding algorithm is polynomial in time and developed by a hierarchical state-encoding scheme, while the verification is performed using side channel analysis. For a set of FSMs, both the feasibility and effectiveness of the proposed FSM-level watermarking approach are demonstrated.