GAMP seminar

Title: Experimentally Secure Relativistic Bit Commitment
Speaker: Matej Pivoluska 

Abstract:
Bit commitment is a well known information primitive used as asubroutine for  different protocols. Unfortunately it is known to be impossible to perform without further limitations, such as limiting the computation power of an adversary. Relativistic bit commitment relays on a more general feature, namely the impossibility of instantaneous communication between distant parties. Here we first derive a tight classical upper bound for the winning probability for a specific family of non-local games, known as CHSH_q(p) and introduced recently in [Chakraborty et. al., PRL 115, 250501, 2015]. Using our bound, we show that the security of relativistic bit commitment of [Lunghi~\textit{et.~al.}, PRL 111, 180504, 2013] against classical adversaries can be extended to any commitment time and distance of the parties that can be expected to be experimentally needed now and in the future -- hence the notion of experimentally secure. For full version of the paper see [arXiv:1601.08095].