Security in Large Networks Using Mediator Protocols

Abstract

This work presents quantum key distribution protocols (QKDPs) to safeguard security in large networks, ushering in new directions in classical cryptography and quantum cryptography. Two mediator protocols, 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.

Existing System

 In classical cryptography, three-party key distribution protocols utilize challengeresponse mechanisms or timestamps to prevent replay attacks.  However, challengeresponse mechanisms require at least two communication rounds between the TC and participants, and the timestamp approach needs the assumption of clock synchronization which is not practical in distributed systems (due to the unpredictable nature of network delays and potential hostile attacks) .  Furthermore, classical cryptography cannot detect the existence of passive attacks such as eavesdropping.

Proposed System

 In quantum cryptography, mediator employ quantum mechanisms to distribute session keys and public discussions to check for eavesdroppers and verify the correctness of a session key.  However, public discussions require additional communication rounds between a sender and receiver and cost precious qubits.

Architecture