Matthew McKague

Self-testing was introduced by Mayers and Yao. The goal of self-testing is to verify the operation of a group of non-communicating quantum devices using only classical interaction with the devices and without trusting any of them a priori. In this article we describe two different self-tests which verify that a group of devices share a graph state and implement Pauli X and Z measurements on this state. The self-tests can be reinterpreted as Bell inequalities which have a unique strategy that achieves the quantum bound.

It has been pointed out Barrett et al. that current protocols for device independent quantum key distribution can leak key to the adversary when devices are used repeatedly and that this issue has not been addressed. We introduce the notion of an insider-proof channel. This allows us to propose a means by which devices with memories could be reused from one run of a device independent quantum key distribution protocol to the next while bounding the leakage to Eve, under the assumption that one run of the protocol could be completed securely using devices with memories.