Erik Woodhead, The Institute of Photonic Sciences, Spain
Quantum key distribution (QKD) can be implemented in both so-called
entanglement-based (EB) and prepare-and-measure (PM) configurations. There is a certain degree of equivalence between EB and PM schemes from the point of view of security analysis that has been heavily exploited in the literature over the last fifteen years or so, where a given PM protocol is reduced to an equivalent EB protocol (following the BBM92 argument) whose security is then proved.
In this talk, I'll consider the security of QKD from the PM point of
view. I'll discuss why this could be desirable, particularly when attempting
to account for the problem of implementation imperfections, and I'll outline how the security of the BB84 protocol can be established, at least in the case of collective attacks, without invoking the BBM92 argument. Finally, I'll introduce the semi-device-independent QKD scenario, in which the goal is to achieve much of the advantage of device-independent QKD, but without requiring entanglement as a resource.