Internal Attack Sample Clauses

Internal Attack. In the QKA protocols, a collusive attack is the most powerful internal attack in which two or more dishonest participants collude together to extract sensitive information or generate the final key alone without revealing their malicious behavior. In this subsection, we show that the proposed model is immune to collusive attacks, such that any group of dishonest participants trying to perform a collusive attack (including the two attack strategies mentioned in section 2) will be detected immediately. Indeed, dishonest participants rely mainly on two important processes to successfully achieve the collusive attack; 1) sharing information about the carrier quantum states that will be used to encode the private data and generate the final key, 2) deceiving the honest participants to deduce their private data by sending forged data. Therefore, to prevent the collusive attack, dishonest participants should be prevented from conducting these two processes. In our protocol, a semi-honest server is used, as indicated in Step (1), to generate the initial quantum states () that will be used to encode the private inputs of the participants. The server shares () with all participants after they receive the encoded data. In that case, all participants use the shared information to deduce the final key fairly. Also, the server checks the security of the quantum channel between every two participants and makes sure that the receiver has received genuine quantum states. Using these two processes, the protocol guarantees that the honest participant has received genuine data, and the dishonest participants cannot obtain useful information to generate the final key alone or steal the private inputs of honest participants.

Internal Attack