Calibratable Polymorphic Temperature Sensor for Detecting Fault Injection and Side-Channel Attacks

Security of a computing system can be compromised by physical attacks against the hardware. Side-channel attacks involve the observation of integrated circuit (IC) or system behavior to extract assets such as cryptographic keys. Fault injection attacks involve the manipulation of underlying circuits to provoke erroneous operations that lead to the escalation of privilege or leakage of secret information. Some side-channel and fault injection attacks force circuits to work at temperatures out of operating range. Several countermeasures have been proposed to detect temperature change. However, they do not perform well in wide temperature fluctuations, have a large overhead area, or introduce other reliability concerns. This paper proposes a calibratable Null Convention Logic-based (NCL) polymorphic sensor that changes its functionality with temperature and can sense whether the temperature goes below or above a carefully designed application-specific threshold. It can be used with a wide range of process technologies without requiring significant modification. Low area overhead, low power consumption, configurable nature, and easy integration make it ideal for ICs. Our results show that this sensor can work at various temperature ranges with reliable operation with ± 1 0 C confidence, 8 μm
²
area and 19.2 μW power overhead, which is approximately 40
$x$
less overhead compared to alternative techniques.