Quantum tomographic cryptography with Bell diagonal states: nonequivalence of classical and quantum distillation protocols

Kaszlikowski, D and Lim, J Y and Oi, D K L and Willeboordse, F H and Gopinathan, A and Kwek, L C (2005) Quantum tomographic cryptography with Bell diagonal states: nonequivalence of classical and quantum distillation protocols. Physical Review A, 71 (1). -. 012309. ISSN 1094-1622

[img]
Preview
PDF
0408088v2.pdf
Preprint

Download (204kB)| Preview

    Abstract

    We present a generalized tomographic quantum key distribution protocol in which the two parties share a Bell diagonal mixed state of two qubits. We show that if an eavesdropper performs a coherent measurement on many quantum ancilla states simultaneously, classical methods of secure key distillation are less effective than quantum entanglement distillation protocols. We also show that certain classes of Bell diagonal states are resistant to any attempt at incoherent eavesdropping.