Non-Local Correlations and Quantum Cryptography

Abstract

Secret sharing, a building block of multiparty cryptography, ensures secure communication of any secret among a set of parties in a way that secret can only be revealed when all of the intended recipients come together and communicate with each other. Where classical cryptography assures computational security only, quantum cryptography promises information-theoretic security through the rules of quantum mechanics which have no classical counterparts such as uncertainty principle, quantum no-cloning theorem, and quantum entanglement. Based on quantum entanglement and hence non-local correlations generated by quantum teleportation and entanglement swapping, I discuss here unconditionally secure and authenticated (2,2) quantum secret sharing scheme for classical secret. Both secrecy and authenticity is assured by the sender through quantum non-local correlations based on quantum teleportation and entanglement swapping. Our security protocol is proved to be secure against internal and external eavesdropping along with the attacks during sharing and reconstruction of secrets for (2,2) threshold scheme. Another feature of this protocol is that it detects both active and passive eavesdropping strategies.