  Networks-on-chips (NoCs) are an integral part of emerging manycore computing
chips. They play a key role in facilitating communication among processing
cores and between cores and memory. To meet the aggressive performance and
energy-efficiency targets of machine learning and big data applications, NoCs
have been evolving to leverage emerging paradigms such as silicon photonics and
wireless communication. Increasingly, these NoC fabrics are becoming
susceptible to security vulnerabilities, such as from hardware trojans that can
snoop, corrupt, or disrupt information transfers on NoCs. This article surveys
the landscape of security challenges and countermeasures across electronic,
wireless, and photonic NoCs.
