Date Added: Jul 2011
With the advent of mobile computing, location-based services have recently gained popularity. Many applications use the location provenance of users, i.e., the chronological history of the users' location for purposes ranging from access control, authentication, information sharing, and evaluation of policies. However, location provenance is subject to tampering and collusion attacks by malicious users. In this paper, the authors examine the secure location provenance problem. They introduce a witness-endorsed scheme for generating collusion-resistant location proofs. They also describe two efficient and privacy preserving schemes for protecting the integrity of the chronological order of location proofs. These schemes, based on hash chains and Bloom filters respectively, allow users to prove the order of any arbitrary subsequence of their location history to auditors.