Quantum secret sharing
Quantum secret sharing (QSS) is a quantum cryptographic scheme for secure communication that extends beyond simple quantum key distribution. It modifies the classical secret sharing (CSS) scheme by using quantum information and the no-cloning theorem to attain the ultimate security for communications. The method of secret sharing consists of a sender who wishes to share a secret with a number of receiver parties in such a way that the secret is fully revealed only if a large enough portion of the receivers work together. However, if not enough receivers work together to reveal the secret, the secret remains completely unknown. The classical scheme was independently proposed by Adi Shamir and George Blakley in 1979. In 1998, Mark Hillery, Vladimír Bužek, and André Berthiaume extended the theory to make use of quantum states for establishing a secure key that could be used to transmit the secret via classical data. In the years following, more work was done to extend the theory to transmitting quantum information as the secret, rather than just using quantum states for establishing the cryptographic key. QSS has been proposed for being used in quantum money as well as for joint checking accounts, quantum networking, and distributed quantum computing, among other applications. (Wikipedia).
