Quantum cryptography: Public key distribution and coin tossing
Cryptography is entering a new age since the first steps that have been made towards quantum computing, which also poses a threat to the classical cryptosystem in general. In this paper, we introduce a new novel encryption technique and algorithm to improve quantum cryptography. The aim of the suggested scheme is to generate a digital signature in quantum computing. An arbitrated digital signature is introduced instead of the directed digital signature to avoid the denial of sending the message from the sender and pretending that the sender's private key was stolen or lost and the signature has been forged. The onetime pad operation that most quantum cryptography algorithms that have been proposed in the past is avoided to decrease the possibility of the channel eavesdropping. The presented algorithm in this paper uses quantum gates to do the encryption and decryption processes. In addition, new quantum gates are introduced, analyzed, and investigated in the encryption and decryption processes. The authors believe the gates that are used in the proposed algorithm improve the security for both classical and quantum computing. (Against)The proposed gates in the paper have plausible properties that position them as suitable candidates for encryption and decryption processes in quantum cryptography. To demonstrate the security features of the algorithm, it was simulated using MATLAB simulator, in particular through the Quack Quantum Library.