Secure & Lightweight Distance-Bounding

Distance-bounding is a practical solution to be used in security-sensitive contexts, mainly to prevent relay attacks. The main challenge when designing such protocols is maintaining their inexpensive cryptographic nature, whilst being able to protect against as many, if not all, of the classical threats posed in their context. Moreover, in distance-bounding, some subtle security shortcomings related to the PRF (pseudorandom function) assumption and ingenious attack techniques based on observing verifiers' outputs have recently been put forward. Also, the recent terrorist-fraud by Hancke somehow recalls once more the need to account for noisy communications in the security analysis of distance-bounding. In this paper, we attempt to incorporate the lessons taught by these new developments in our distance-bounding protocol design. The result is a new class of protocols, with increasing levels of security, accommodating the latest advances; at the same time, we preserve the lightweight nature of the design throughout the whole class.