QUANTUM LOCKING OF CLASSICAL CORRELATIONS AND QUANTUM DISCORD OF CLASSICAL-QUANTUM STATES
2011 ◽
Vol 09
(07n08)
◽
pp. 1643-1651
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Keyword(s):
A locking protocol between two parties is as follows: Alice gives an encrypted classical message to Bob which she does not want Bob to be able to read until she gives him the key. If Alice is using classical resources, and she wants to approach unconditional security, then the key and the message must have comparable sizes. But if Alice prepares a quantum state, the size of the key can be comparatively negligible. This effect is called quantum locking. Entanglement does not play a role in this quantum advantage. We show that, in this scenario, the quantum discord quantifies the advantage of the quantum protocol over the corresponding classical one for any classical-quantum state.
2011 ◽
Vol 18
(04)
◽
pp. 339-351
◽
2012 ◽
Vol 27
(01n03)
◽
pp. 1345041
◽
2014 ◽
Vol 12
(01)
◽
pp. 1450004
◽
Keyword(s):
2011 ◽
Vol 09
(06)
◽
pp. 1437-1448
Keyword(s):
2011 ◽
Vol 11
(6)
◽
pp. 1931-1950
◽