Distance bounding overview

Distance bounding overview ● Mafia fraud: an adversary tricks a verifier into thinking that a prover is near, by establishing a relay link between them ● Distance fraud: the prover itself is malicious, and tricks the verifier into thinking to be near Distance bounding overview ● A distance bounding protocol permits us to establish a secure upper bound (D) to the distance between a “prover ” and a “verifier”: d < = D ● The basic idea is to precisely measure the round-trip time between two unpredictable messages (a challenge and a response) Distance bounding overview D max DV The prover is surely in this circle Brands-Chaum protocol (type I) Prover Verifier a i sign k(m) secret key: k N random bits: aiN random bits: b