Secure key distribution among classical parties is impossible both between two parties and in a network. In this paper, we present a quantum key distribution (QKD) protocol to distribute secure key bits among one quantum party and numerous classical parties who have no quantum capacity. We prove that our protocol is completely robust, i.e., any eavesdropping attack should be detected with nonzero probability. Our calculations show that our protocol may be secure against Eve's symmetrically individual attack.
Secure key distribution among classical parties is impossible both between two parties and in a network. In this paper, we present a quantum key distribution (QKD) protocol to distribute secure key bits among one quantum party and numerous classical parties who have no quantum capacity. We prove that our protocol is completely robust, i.e., any eavesdropping attack should be detected with nonzero probability. Our calculations show that our protocol may be secure against Eve's symmetrically individual attack.
It seems that quantum key distribution (QKD) may be completely insecure when the message sender Alice always encodes her key bits in a fixed basis. In this paper, we present a QKD protocol with classical Alice, i.e. Alice always encodes her key bit in the {|0〉,|1〉} basis (we call it classical {0,1} basis) and the eavesdropper Eve knows this fact. We prove that our protocol is completely robust against any eavesdropping attack and present the amount of tolerable noise against Eve's individual attack. Next, we present a QKD protocol to demonstrate that secure key bits can be distributed even if neither Alice nor Bob has quantum capacities, and extend this idea to a QKD network protocol with numerous parties who have only classical capacities. Finally, we discuss that quantum is necessary in QKD for security reasons, but both Alice and Bob may be classical.
Secure key distribution among two remote parties is impossible when both are classical, unless some unproven computation-complexity assumptions are made, such as the difficulty of factorizing large numbers. On the other hand, a secure key distribution is possible when both parties are quantum. What is possible when only one party (Alice) is quantum, yet the other (Bob) has only classical capabilities? We present a protocol with this constraint and prove its robustness against attacks: we prove that any attempt of an adversary to obtain information necessarily induces some errors that the legitimate users could notice.
Secure key distribution among two remote parties is impossible when both are classical, unless some unproven (and arguably unrealistic) computation-complexity assumptions are made, such as the difficulty of factorizing large numbers. On the other hand, a secure key distribution is possible when both parties are quantum. What is possible when only one party (Alice) is quantum, yet the other (Bob) has only classical capabilities? We present two protocols with this constraint, and prove their robustness against attacks: we prove that any attempt of an adversary to obtain information (and even a tiny amount of information) necessarily induces some errors that the legitimate users could notice.
This paper proposes a novel secure communication protocol based on Quantum Key Distribution (QKD). The core claim is to design a protocol capable of completely secure key transmission, resisting eavesdropping and manipulation, thereby guaranteeing communication security. The protocol leverages quantum entanglement to facilitate quantum key transmission and employs cryptographic algorithms for key encryption and decryption. Traditional secure communication protocols relying on classical key exchange are vulnerable to attacks. QKD offers a significantly higher level of security. This document details the protocol's architecture, mathematical formulation of the key exchange process, and the security analysis underpinning its design. The focus is on demonstrating a robust system against known classical and quantum attacks, providing a foundation for future secure communication networks. The system is designed for a two-party communication scenario, aiming for maximal security with reasonable complexity.
Secure key distribution between two remote parties is impossible when both are classical, unless some unproven (and arguably unrealistic) computation-complexity assumptions are made, such as the difficulty of factorizing large numbers. On the other hand, a secure key distribution is possible when both parties are quantum. What is possible when only one party (Alice) is quantum, yet the other (Bob) has only classical capabilities? Recently, a semiquantum key distribution protocol was presented [M. Boyer, D. Kenigsberg, and T. Mor, Phys. Rev. Lett. 99, 140501 (2007)], in which one of the parties (Bob) is classical, and yet, the protocol is proven to be completely robust against an eavesdropping attempt. Here we extend that result much further. We present two protocols with this constraint and prove their complete robustness against attacks: we prove that any attempt of an adversary to obtain information (and even a tiny amount of information) necessarily induces some errors that the legitimate parties could notice. One protocol presented here is identical to the one referred to above; however, its robustness is proven here in a much more general scenario. The other protocol is very different as it is based on randomization.
The traditional security system, which depends on asymmetric and symmetric key exchange protocol, is now under threat due to recent developments in quantum computing. In order to generate the safe key without storing the qubit by the sender or recipient trustworthy parties, a unique Quantum Key Distribution (QKD) protocol was presented. Four random classical bits coupled to generate a pair of bell states in any of the places {(1,2,3,4), (1,3,2,4) and (1,4,2,3)}. "n/2" groups were used to generate the raw key while the remaining groups were used to check for Eve. The flying bell states scatter into four separate bell states as a result of Eve's involvement in choosing the incorrect measurement basis, which causes entanglement swapping and its identification during communication. The sender will alter the key in accordance with the receiver's position preference because, in traditional communication, key receiving parties must announce the position information. Under the intercept-measure-resend attack, the trade-off between the key generating rate and disturbance is computed and security is examined. Circuit simulation is demonstrated graphically in IBM Quantum Lab and the proposed protocol is implemented.