Provably Dwindling Three-Party Spurious Classical and Quantum Key Distribution Protocols

This chapter presents quantum key distribution protocols (QKDPs) to safeguard security in large networks, ushering in new directions in classical cryptography and quantum cryptography. Two three-party QKDPs, one with implicit user authentication and the other with explicit mutual authentication, are proposed to demonstrate the merits of the new combination, which include the following: 1) Security against such attacks as man-in-the-middle, eavesdropping, and replay, 2) Efficiency is improved as the proposed protocols contain the fewest number of communication rounds among existing QKDPs, and 3) Two parties can share and use a long-term secret (repeatedly). To prove the security of the proposed schemes, this work also presents a new primitive called the unbiased-chosen basis (UCB) assumption.