Secure, Private Proofs of Location
We present the design of a system that can securely prove the
location of a mobile device. In our system the device attempts
to prove its location to a party known as the Verifier
using a local network. We designed a protocol that
securely measures the proximity of the device to the local network.
We accomplish this by securely measuring the round-trip signal
propagation latency. This technique protects the protocol from
powerful attacks by an adversary. The protocol maintains the identity
of the device and Verifier as private. We believe we are the first
to design a location-proving system that offers both integrity and privacy.
Additionally, we provide a solution to deciding which local networks
are suitable for location proving. Finally, we show how our basic
protocol can be adapted to securely prove the exact position
of a tamper-resistant
device even when the device is in the possession of an adversary.