Physically Unclonable Reflecting Intelligent Surfaces for Cyber-Physical Security in Smart Wireless Networks

Enormous research efforts have been witnessed in recent years to configure smart wireless networks with the emerging technology of Reflecting Intelligent Surfaces (RISs), thus enabling the innovative construction of intelligent and adaptive wireless environments. However, the successful deployment of RIS-assisted cyber-physical systems requires large-scale implementations of RIS devices across extensive areas. Consequently, RIS-aided wireless networks become susceptible to impersonation cyber-attacks, where unauthorized RISs can be disguisedly injected into the network and execute harmful activities to violate communication security. This paper introduces a cyberattack countermeasure based on leveraging unavoidable intrinsic tolerance of RIS to architect unique and unclonable fingerprints for each device. Similar to human fingerprints, no two designed RISs share identical fingerprints as it has been validated by numerical and full-wave analyses. This proposed structure is the first physical-unclonable RIS (PU-RIS) and is expected to revolutionize the cyber-security of smart wireless networks, where RIS utilization is unavoidable as predicted by leading experts.