A note on "new quantum key agreement protocols based on Bell states (original) (raw)
Comment on "Quantum key agreement protocol
ArXiv, 2020
The first two party Quantum Key Agreement (QKA) protocol, based on quantum teleportation, was proposed by Zhou et al. (Electronics Letters 40.18 (2004): 1149-1150). In this protocol, to obtain the key bit string, one of the parties use a device to obtain inner product of two quantum states, one being unknown, and the other one performs Bell measurement. However, in this article, we show that it is not possible to obtain a device that would output the inner product of two qubits even when only one of the qubit is unknown. This is so because existence of such device would imply perfectly distinguishing among four different states in a two-dimensional vector space. This is not permissible in quantum mechanics. Furthermore, we argue that existence of such a device would also imply violation of the ``No Signalling Theorem" as well. Finally, we also comment that this protocol is not a valid key agreement protocol at all.
Reply to Comment on ‘Authenticated quantum secret sharing with quantum dialogue based on Bell states
Physica Scripta, 2018
In the Comment made by Gao (2018 Phys. Scr. 93 027002), it has been shown that the multiparty case in our proposed scheme in Abulkasim et al (2016 Phys. Scr. 91 085101) is not secure, where Bob and Charlie can deduce Alice's unitary operations without being detected. This reply shows a simple modification of the multiparty case to prevent the dishonest agents from performing this kind of attack.
Semi-quantum Key Distribution Protocol Based on Bell States
International journal of security and its applications, 2016
A quantum key distribution protocol with traditional Bob has been proposed recently by Boyer et al. using single-particle state. In this paper, a semi-quantum key distribution protocol is described, in which Einstein-Podolsky-Rosen (EPR) pairs of particles are utilized to generate a secret key in remote places. This extends the quantum key distribution protocol with traditional Bob where the single-qubit channel is replaced by the entangled EPR-pair channel. And quantum Alice is able to do any quantum operations, preparing quantum states and performing quantum measurement, but traditional Bob is not able to prepare and measure a particle in the computational basis, reflect the particles. Furthermore, entanglement states are used in our protocol. The analysis shows that our protocol is secure, which can avoid the beam splitter attack automatically, and the proposed protocol is more efficient than Boyer's scheme.
International Journal of Mathematical Sciences and Computing, 2017
Quantum cryptography is marches towards secure communication by using quantum protocols. Number of quantum protocols has been evolved based on an entanglement in three decades; similarly during this meanwhile non-entanglement based protocols have been evolved within the same period also. Among number of different protocols a torch bearer was BB84 protocol. Even though different quantum communication protocols exist, the BB84 protocol proved its application by initial experiments whereas most of the other protocols are theoretical which marches towards the practical application yet. But in quantum mechanics principle, cryptography based on an entanglement and superposition of entangled particle. Furthermore, challenges ahead are development and design high sensitive equipments for measurement of an entangled particle position at output end. Particle entanglements open a new door for computation worlds such as speedup, security. In this article, we discuss quantum protocols, their challenges, and applications based on above discussion.
An efficient quantum identity authentication key agreement protocol without entanglement
Quantum Information Processing, 2020
Quantum identity authentication key agreement (QIAKA) protocols are designed to allow two nodes to establish a secure secret key when they require few resources, such as a few shared secret bits, and it is technologically feasible. However, the existing studies have two main flaws: they divided quantum identity authentication and key agreement into two realms to research, not integrated them. On the other side, the existing quantum identity authentication has many safety loopholes with inefficiency. In this paper, we firstly devise a quantum identity authentication key agreement protocol without entanglement to improve the efficiency and wipe out any node to know the session key expect the involved parties. In our proposed protocol, through revising the mode and parameters, both the security and efficiency are improved greatly. Furthermore, the short shared secret key is dynamic change at the end of the proposed protocol. Compared with the related literature recently, our proposed scheme can not only own high efficiency and unique functionality, but is also robust to various attacks and the security proof is suitable for the single-state QIAKA protocol.
Quantum Information Processing
Kak's three-stage protocol for quantum key distribution is revisited with special focus on its hitherto unknown strengths and weaknesses. It is shown that this protocol can be used for secure direct quantum communication. Further, the implementability of this protocol in the realistic situation is analyzed by considering various Markovian noise models. It is found that the Kak's protocol and its variants in their original form can be implemented only in a restricted class of noisy channels, where the protocols can be transformed to corresponding protocols based on logical qubits in decoherence free subspace. Specifically, it is observed that Kak's protocol can be implemented in the presence of collective rotation and collective dephasing noise, but cannot be implemented in its original form in the presence of other types of noise, like amplitude damping and phase damping noise. Further, the performance of the protocol in the noisy environment is quantified by computing average fidelity under various noise models, and subsequently a set of preferred states for secure communication in noisy environment have also been identified.
Deterministic and efficient quantum cryptography based on Bell’s theorem
Physical Review A, 2006
We propose a double-entanglement-based quantum cryptography protocol that is both efficient and deterministic. The proposal uses photon pairs with entanglement both in polarization and in time degrees of freedom; each measurement in which both of the two communicating parties register a photon can establish one and only one perfect correlation, and thus deterministically create a key bit. Eavesdropping can be detected by violation of local realism. A variation of the protocol shows a higher security, similar to the six-state protocol, under individual attacks. Our scheme allows a robust implementation under the current technology.
Detecting two-party quantum correlations in quantum-key-distribution protocols
2005
A necessary precondition for secure quantum key distribution (QKD) is that sender and receiver can prove the presence of entanglement in a quantum state that is effectively distributed between them. In order to deliver this entanglement proof one can use the class of entanglement witness (EW) operators that can be constructed from the available measurements results. This class of EWs can be used to provide a necessary and sufficient condition for the existence of quantum correlations even when a quantum state cannot be completely reconstructed. The set of optimal EWs for two well-known entanglement based (EB) schemes, the 6-state and the 4-state EB protocols, has been obtained recently [M. Curty et al., Phys. Rev. Lett. 92, 217903 (2004)]. Here we complete these results, now showing specifically the analysis for the case of prepare&measure (P&M) schemes. For this, we investigate the signal states and detection methods of the 4-state and the 2-state P&M schemes. For each of these protocols we obtain a reduced set of EWs. More importantly, each set of EWs can be used to derive a necessary and sufficient condition to prove that quantum correlations are present in these protocols.