@inproceedings{crypto-2011-23588,
title={Position-Based Quantum Cryptography: Impossibility and Constructions},
booktitle={Advances in Cryptology - CRYPTO 2011 - 31st Annual Cryptology Conference},
series={Lecture Notes in Computer Science},
publisher={Springer},
volume={6841},
pages={423},
author={Harry Buhrman and Nishanth Chandran and Serge Fehr and Ran Gelles and Vipul Goyal and Rafail Ostrovsky and Christian Schaffner},
year=2011
}