Intellectual property (IP) core reuse is essential for the design process of system-on-chip (SoC). Network-on-chip (NoC) has been used as an independent IP core during SoC design. However, the NoC has not been protected via IP protection and paid attention on its innovations. This paper proposes the first known approach to protect the authorship and the usage legitimacy of NoCs using specially designed routing, square spiral routing. The special routing algorithm exploits routing redundancy inherent in the mesh NoCs and transports packets along the paths, which have very low probability to be taken under commonly used routing algorithms. These unique and diverse paths are exploited in this paper to embed information of the author and identify the legal buyer of NoCs, showing high robustness and credibility. The hardware implementation of an IP-protected mesh NoC shows that the area overhead is small, which is    $\sim 0.74$   %, and the power overhead is    $\sim 0.52$   %, while the functionality and performance of the network is not affected. In this paper, the approach is presented for the mesh NoC, but the idea is equally applicable to other NoC topologies where the unique and diverse paths also inherently exist.
['Qiang Liu', 'Wenqing Ji', 'Qi Chen', 'Terrence S. T. Mak']
IP Protection of Mesh NoCs Using Square Spiral Routing