Quantum state sharing
Andrew M. Lance, Thomas Symul, Warwick P. Bowen, Barry C. Sanders, Ping Koy Lam · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2004
We demonstrate a multipartite protocol that utilizes entanglement to securely distribute and reconstruct a quantum state. A secret quantum state is encoded into a tripartite entangled state and distributed to three players. By collaborating together, a majority of the players can reconstruct the state, whilst the remaining player obtains nothing. This (2,3) threshold quantum state sharing scheme is characterized in terms of fidelity (F), signal transfer (T) and reconstruction noise (V). We demonstrate a fidelity averaged over all reconstruction permutations of 0.73 ± 0.04, a level achievable only using quantum resources.