A theoretical scheme for controlled and secure direct communication is proposed. The communication is based on GHZ state and controlled quantum teleportation. After insuring the security of the quantum channel (a set of qubits in the GHZ state), Alice encodes the secret message directly on a sequence of particle states and transmits them to Bob supervised by Charlie using controlled quantum teleportation. Bob can read out the encoded messages directly by the measurement on his qubits. In this scheme, the controlled quantum teleportation transmits Alice's message without revealing any information to a potential eavesdropper. Because there is not a transmission of the qubit carrying the secret messages between Alice and Bob in the public channel, it is completely secure for controlled and direct secret communication if perfect quantum channel is used. The feature of this scheme is that the communication between two sides depends on the agreement of the third side.
Comment on Quantum teleportation via GHZ-like state
最近Yang等人[Int. J. Theo. Phys.48(2009)516]已经表明,可以通过使用特定的类GHZ状态作为量子信道来传送未知的量子比特。然而,在计算中存在一些错误,导致不正确的结论。错误已经指出并纠正。值得注意的是,他们的方案和张等人独立提出的隐形传态方案[Int. J. Theo. Phys.48(2009)3331]使用来自同一族的量子信道,并且该族的任何状态都可以用于隐形传态。
Improvement of bidirectional controlled teleportation by using a five-qubit composite GHZ-Bell state
最近,李和聂(国际J。52:1630,2013)通过使用GHZ-贝尔态作为量子信道引入了双向受控量子隐形传态(BCQT)协议。此外,Shukla等人(Int. J. Theo. 52:3790,2013)已经表明Li和Nie(LN)方案不是BCQT方案。本文提出了两种双向隐形传态方案,对LN协议进行了修正和改进。在第一个方案中,Alice和Bob作为两个合法用户,可以在控制者Charlie的帮助下同时传送一个未知的单比特态给对方。在第二种方案中,Alice可以向Bob传送两个量子比特的纠缠态,同时Bob可以向Alice传送单量子比特的量子态。在这两种方案中,用户间的量子信道都是GHZ Bell态。
Practical quantum teleportation with finite-energy codebooks
Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften(瓦尔特·迈斯纳研究所,巴伐利亚科学院);School of Natural Sciences, Technical University of Munich(慕尼黑工业大学自然科学院);Munich Center for Quantum Science and Technology (MCQST)(慕尼黑量子科学与技术中心)
We propose a scheme of repeated generalized Bell state measurement (GBSM) for probabilistic quantum teleportation of single qubit state of a particle (say, 0) using 3-qubit non-maximally entangled (NME) GHZ state as a quantum channel. Alice keeps two qubits (say, 1 and 2) of the 3-qubit resource and the third qubit (say, 3) goes to Bob. Initially, Alice performs GBSM on qubits 0 and 1 which may lead to either success or failure. On obtaining success, Alice performs projective measurement on qubit 2 in the eigen basis of $σ_{x}$. Both these measurement outcomes are communicated to Bob classical…
We prove that the teleportation based quantum cryptography protocol presented in [Opt. Commun. 283, 184 (2010)], which is built using only orthogonal states encoding the classical bits that are teleported from Alice to Bob, is asymptotically secure against all types of individual and collective attacks. We then investigate modifications to that protocol leading to greater secret-key rates and to security against coherent attacks. In other words, we show an unconditional secure quantum key distribution protocol that does not need non-orthogonal quantum states to encode the bits of the secret ke…
Recently, Yu et al., (Commun. Theor. Phys. 73 (2021) 085103) has proposed a scheme for "multi-output quantum teleportation" and has implemented the scheme using an IBM quantum computer. In their so called multicast-based quantum teleportation scheme, a sender (Alice) teleported two different quantum states (one of which is a m-qubit GHZ class state and the other is a (m+1)-qubit GHZ class state) to the two receivers. To perform the task, a five-qubit cluster state was used as a quantum channel, and the scheme was realized using IBM quantum computer for m = 1. In this comment, it is shown that …
Improving the probabilistic quantum teleportation efficiency of arbitrary superposed coherent state using multipartite even and odd j-spin coherent states as resource
Secure Quantum Secret Sharing Based on Reusable GHZ States as Secure Carriers
我们证明了当合法用户使用安全载体在协议中重复地对经典信息进行编码和解码时,潜在的窃听者可以窃听整个秘密信息[Bagherinezhad S和Karimipour V 2003 Phys. Rev. A \textbf{67} 044302中提出]。在此基础上,我们提出了一个改进的量子秘密共享协议,该协议以Greenberger-Horne-Zeilinger态为安全载体。我们的协议可以抵抗夏娃的攻击
We present a scheme to generate a continuous variable (CV) multipartite entangled state using an array of plasmonic graphene waveguides that are activated by nonclassical driving microwave modes. Within this scheme, we can exploit the interaction of two light fields coupled to the same microwave mode in each waveguide to produce any type of multipartite Gaussian entangled state. A teleportation network is illustrated using the resultant CV multipartite entangled state. In particular, the proposed setup enables coherent state teleportation across remotely connected nodes with fidelity above a t…
Very recently, Lee et al. proposed the first secure quantum teleporation protocol, where quantum information shared by an arbitrary number of senders can be transferred to another arbitrary number of receivers. Here, by introducing quantum walks, a novel secure (n,m) quantum teleportation of shared quantum secret between n senders and $m$ receivers is presented. Firstly, two kinds of (n,2) teleportation schemes are proposed by n-walker quantum walks on the line, the first walker of which is driven by three coins, respectively, based on two kinds of coin operators: the homogeneous coins and the…
Bidirectional quantum teleportation is a fundamental protocol for exchanging quantum information between two quantum nodes. All bidirectional quantum teleportation protocols till now have achieved a maximum efficiency of $40\%$. Here, we propose a new scheme for symmetric bidirectional quantum teleportation using a six-qubit cluster state as the quantum channel, for symmetric ($3\leftrightarrow3$) qubit bidirectional quantum teleportation of a special three-qubit entangled state. The novelty of our scheme lies in its generalization for ($N\leftrightarrow N$) qubit bidirectional quantum telepor…