  Secure distance bounding (DB) protocols allow one entity, the verifier, to
securely obtain an upper-bound on the distance to another entity, the prover.
Thus far, DB was considered mostly in the context of a single prover and a
single verifier. There has been no substantial prior work on secure DB in group
settings, where a set of provers interact with a set of verifiers. The need for
group distance bounding (GDB) is motivated by many practical scenarios,
including: group device pairing, location-based access control and secure
distributed localization. GDB is also useful in mission-critical networks and
automotive computer systems. This paper addresses, for the first time, GDB
protocols by utilizing the new passive DB primitive and the novel mutual
multi-party GDB protocol. We show how they can be used to construct secure and
efficient GDB protocols for various settings. We analyze security and
performance of our protocols and compare them with existing DB techniques when
applied to group settings.
