Location-Oblivious Data Transfer with Flying Entangled Qudits
  We present a simple and practical quantum protocol involving two mistrustful agencies in Minkowski space, which allows Alice to transfer data to Bob at a spacetime location that neither can predict in advance. The location depends on both Alice's and Bob's actions. The protocol guarantees unconditionally to Alice that Bob learns the data at a randomly determined location; it guarantees to Bob that Alice will not learn the transfer location even after the protocol is complete.   The task implemented, transferring data at a space-time location that remains hidden from the transferrer, has no precise analogue in non-relativistic quantum cryptography. It illustrates further the scope for novel cryptographic applications of relativistic quantum theory. 
Adrian Kent (Centre for Quantum Information and Foundations, DAMTP,   University of Cambridge and Perimeter Institute for Th...
quant-ph cs.CR cs.IT math.IT