Sequence Of Single Photons Research Articles

Multiparty semi-quantum secret sharing protocol based on single photon sequence and permutation

Most semi-quantum secret sharing protocols are suitable for the application with three participants. Based on the n-level states, a multiparty semi-quantum secret sharing protocol is proposed. Compared with similar protocols, it has the merits as follows. (1) The dealer only needs to prepare the single photon sequence without using any product state or entangle state. (2) To share a secret, the classical parties need not have the ability of measurement. They only need to reorder the photon sequence and send it to the receiver. (3) The dealer knows nothing about any agent’s secret shadow. Therefore, it is infeasible for the dealer to impersonate the classical participant to pool the secret shadow during the secret recovering phase. (4) Theoretically, the qubit efficiency of the proposed protocol is asymptotically 100%. The protocol is secure against famous attacks such as intercept-resend attack, measurement-resend attack and entangle-measure attack.

Quantum Multi-User Broadcast Protocol for the "Platform as a Service" Model.

Quantum Cloud Computing is the technology which has the capability to shape the future of computing. In “Platform as a Service (PaaS)” type of cloud computing, the development environment is delivered as a service. In this paper, a multi-user broadcast protocol in network is developed with the mode of one master and N slaves together with a sequence of single photons. It can be applied to a multi-node network, in which a single photon sequence can be sent to all the slave nodes simultaneously. In broadcast communication networks, these single photons encode classical information directly through noisy quantum communication channels. The results show that this protocol can realize the secret key generation and sharing of multiple nodes. The protocol we propose is also proved to be unconditionally secure in theory, which indicates its feasibility in theoretical application.

Single-photon scattering in an optomechanical Jaynes-Cummings model

We investigate an optomechanical system which realizes the Jaynes-Cummings (JC) model known in cavity QED. Such a system consists of a single photon and an optomechanical cavity with two optical cavity modes and one mechanical mode. Under the resonance condition when the mechanical frequency is close to the frequency difference between the optical modes, the photon and phonons can be strongly coupled. We present an analytic solution of single-photon scattering and show that the spectrum of the scattered photon exhibits excitation-number-dependent Rabi splitting of the JC model. In addition, we examine the response of the mechanical mode to a sequence of single photons, with one photon in the cavity at a time. We show that sequential photon scattering can efficiently excite the mechanical mode and generate sub-Poisson phonon statistics.

Quantum Secure Communication Protocol Based on Single-photon

Two-way quantum secure communication protocol and one-way quantum secure communication protocol based on single photon sequence and the XOR operation have been proposed, one-way communication can confuse the eavesdroppers and two-way communication only a single authentication and there is not visible to eavesdropping and delayed photon attack Trojan horse attack. The new agreement the use of single photon sequence and no regularity not only to achieve unconditional security, and semantics confuse eavesdroppers and has a high transmission efficiency, easy implementation, especially suitable for use in noisy channels.

CNOT extraction attack on “quantum asymmetric cryptography with symmetric keys”

This paper is based on previous quantum encryption proposed by researchers developing a scheme for cryptography using symmetric keys. This study has pointed out that the scheme consists of a pitfall that could lead to a controlled-NOT (CNOT) extraction attack. A malicious user can obtain the secret message of a sender without being detected by using a sequence of single photons and a controlled-NOT gate.

Robust Quantum Secure Communication with Spatial Quantum States of Single Photons

The polarization quantum states of photon systems are fragile to the channel noise. However, recent experiments showed that the spatial quantum states of photon systems are robust. Recently, Ren et al. proposed a robust quantum secure direct communication (QSDC) protocol with spatial entanglement (Ren et al., Eur. Phys. J. D 67:30, 2013). Here we proposed a robust QSDC protocol and a robust three-party quantum secret sharing protocol with the four nonorthogonal spatial quantum states of a sequence of single photons, respectively. Both these two quantum secure communication protocols have the advantage of having a robust character and not increasing the difficulty of their implementations in experiment, compared with almost all the existing quantum secure communication protocols which are based on the polarization quantum states of photon systems. Moreover, they are more feasible than the QSDC protocol by Ren et al. as they do not require Bell-state measurements.

High-Capacity Three-Party Quantum Secret Sharing with Single Photons in Both the Polarization and the Spatial-Mode Degrees of Freedom

We present a high-capacity three-party quantum secret sharing (QSS) protocol with a sequence of single photons in both the polarization and the spatial-mode degrees of freedom. By inserting the boss Alice into the middle position between the two agents Bob and Charlie, our QSS protocol is secure in theory. The boss Alice chooses some unitary operations to encode her information on the single photons. It is interesting to point out the fact that Alice does not change the bases of the single photons which are used to carry the useful information about the private key, which improves its success probability for obtaining a private key. Compared with the QSS protocol by Zhou et al. (Chin. Phys. Lett. 24, 2181 (2007)), our QSS protocol has a higher capacity without increasing the difficulty of its implementation in experiment as each correlated photon can carry two bits of useful information. Compared with those QSS protocols based on entangled photon pairs and Bell-state measurements, our QSS protocol is more feasible as it does not require the complete Bell-state analysis which is not easy with linear optics. We give out the setup for the implementation of our QSS protocol with linear optical elements.

Quantum secret sharing between m-party and n-party with six states

We propose a quantum secret sharing scheme between $m$-party and $n$-party using three conjugate bases, i.e. six states. A sequence of single photons, each of which is prepared in one of the six states, is used directly to encode classical information in the quantum secret sharing process. In this scheme, each of all $m$ members in group 1 choose randomly their own secret key individually and independently, and then directly encode their respective secret information on the states of single photons via unitary operations, then the last one (the $m$th member of group 1) sends $1/n$ of the resulting qubits to each of group 2. By measuring their respective qubits, all members in group 2 share the secret information shared by all members in group 1. The secret message shared by group 1 and group 2 in such a way that neither subset of each group nor the union of a subset of group 1 and a subset of group 2 can extract the secret message, but each whole group (all the members of each group) can. The scheme is asymptotically 100% in efficiency. It makes the Trojan horse attack with a multi-photon signal, the fake-signal attack with EPR pairs, the attack with single photons, and the attack with invisible photons to be nullification. We show that it is secure and has an advantage over the one based on two conjugate bases. We also give the upper bounds of the average success probabilities for dishonest agent eavesdropping encryption using the fake-signal attack with any two-particle entangled states. This protocol is feasible with present-day technique.

One-way quantum identity authentication based on public key

Based on public key, a quantum identity authenticated (QIA) system is proposed without quantum entanglement. The public key acts as the authentication key of a user. Following the idea of the classical public key infrastructure (PKI), a trusted center of authentication (CA) is involved. The user selects a public key randomly and CA generates a private key for the user according to his public key. When it is necessary to perform QIA, the user sends a sequence of single photons encoded with its private key and a message to CA. According to the corresponding secret key kept by CA, CA performs the unitary operations on the single photon sequence. At last, the receiver can judge whether the user is an impersonator.

Development of quantum network based on multiparty quantum secret sharing

In this paper, we develop a quantum network with a mutual quantum secure direct communication scheme based on multiparty quantum secret sharing. This quantum network, assumed to contain clusters S, M, and D, shares a sequence of single photons and Greenberger–Horne–Zeilinger (GHZ) states. Each cluster is made of the same or similar quantum nodes gathered or occurring closely together. The feature of this scheme is that the communication between two clusters depends on the agreement of the third cluster. We also prove that such a quantum network is unconditionally secure.PACS Nos.: 03.67.–Dd, 03.67.–Hk, 89.70.–a

Threshold quantum secret sharing between multi-party and multi-party

A threshold quantum secret sharing (TQSS) scheme between multi-party and multi-party was proposed using a sequence of single photons, which is useful and efficient when the parties of communication are not all present. We described the process of this TQSS scheme and discussed its security. It was shown that entanglement is not necessary for quantum secret sharing. Moreover, the theoretic efficiency was improved to approach 100% as almost all the instances can be used for generating the private key, and each photon can carry one bit of information. This protocol is feasible with the present-day technique.

Quantum Secret Sharing Protocol between Multiparty and Multiparty with Single Photons and Unitary Transformations

We propose a scheme of quantum secret sharing between Alice's group and Bob's group with single photons and unitary transformations. In the protocol, one member in Alice's group prepares a sequence of single photons in one of four different states, while other members directly encode their information on the sequence of single photons via unitary operations; after that, the last member sends the sequence of single photons to Bob's group. Then Bob's, except for the last one, do work similarly. Finally the last member in Bob's group measures the qubits. If the security of the quantum channel is guaranteed by some tests, then the qubit states sent by the last member of Alice's group can be used as key bits for secret sharing. It is shown that this scheme is safe.

Multiparty simultaneous quantum identity authentication with secret sharing

Two multiparty simultaneous quantum identity authentication (MSQIA) protocols based on secret sharing are presented. All the users can be authenticated by a trusted third party (TTP) simultaneously. In the first protocol, the TTP shares a random key K with all the users using quantum secret sharing. The ith share acts as the authentication key of the ith user. When it is necessary to perform MSQIA, the TTP generates a random number R secretly and sends a sequence of single photons encoded with K and R to all the users. According to his share, each user performs the corresponding unitary operations on the single photon sequence sequentially. At last, the TTP can judge whether the impersonator exists. The second protocol is a modified version with a circular structure. The two protocols can be efficiently used for MSQIA in a network. They are feasible with current technology.

Threshold quantum secure direct communication without entanglement

For the first time, a threshold quantum secure direct communication (TQSDC) scheme is presented. Similar to the classical Shamir’s secret sharing scheme, the sender makes n shares, S 1, ..., S n of secret key K and each receiver keeps a share secretly. If the sender wants to send a secret message M to the receivers, he encodes the information of K and M on a single photon sequence and sends it to one of the receivers. According to the secret shares, the t receivers sequentially perform the corresponding unitary operations on the single photon sequence and obtain the secret message M. The shared shares may be reusable if it can be judged that there is no eavesdropper in line. We discuss that our protocol is feasible with current technology.

Circular threshold quantum secret sharing

This paper proposes a circular threshold quantum secret sharing (TQSS) scheme with polarized single photons. A polarized single photon sequence runs circularly among any t or more of n parties and any t or more of n parties can reconstruct the secret key when they collaborate. It shows that entanglement is not necessary for quantum secret sharing. Moreover, the theoretic efficiency is improved to approach 100% as the single photons carrying the secret key are deterministically forwarded among any t or more of n parties, and each photon can carry one bit of information without quantum storage. This protocol is feasible with current technology.

Scheme for generating a sequence of single photons of alternating polarization

Single-photons of well-defined polarization that are deterministically generated in a single spatio-temporal field mode are the key to the creation of multi-partite entangled states in photonic networks. Here, we present a novel scheme to produce such photons from a single atom in an optical cavity, by means of vacuum-stimulated Raman transitions between the Zeeman substates of a single hyperfine state. Upon each transition, a photon is emitted into the cavity, with a polarization that depends on the direction of the Raman process.

Persistent single-photon production by tunable on-chip micromaser with a superconducting quantum circuit

We propose a tunable on-chip micromaser using a superconducting quantum circuit (SQC). By taking advantage of externally controllable state transitions, a state population inversion can be achieved and preserved for the two working levels of the SQC and, when needed, the SQC can generate a single photon. We can regularly repeat these processes in each cycle when the previously generated photon in the cavity is decaying, so that a periodic sequence of single photons can be produced persistently. This provides a controllable way for implementing a persistent single-photon source on a microelectronic chip.

Multiparty controlled quantum secure direct communication protocol

Based on the order rearrangement of single photon sequence, we present a multiparty controlled quantum secure direct communication protocol. The present protocol can be applied to some special scenario. In the protocol, the sender's secret message can only be recovered by the receiver under the permission of all the controllers. The security for the protocol is ensured by the quantum no-cloning theorem and the secret transmitting order of the single photon sequence. Moreover, all photons are used to encode the secret message except those chosen for eavesdropping check and it is unnecessary for the protocol to use entanglement. Our protocol is efficient and practicable.

Quantum secret sharing between multiparty and multiparty without entanglement

We propose a quantum secret sharing protocol between multiparty ($m$ members in group 1) and multiparty ($n$ members in group 2) using a sequence of single photons. These single photons are used directly to encode classical information in a quantum secret sharing process. In this protocol, all members in group 1 directly encode their respective keys on the states of single photons via unitary operations; then, the last one (the $m\mathrm{th}$ member of group 1) sends $1∕n$ of the resulting qubits to each of group 2. Thus the secret message shared by all members of group 1 is shared by all members of group 2 in such a way that no subset of each group is efficient to read the secret message, but the entire set (not only group 1 but also group 2) is. We also show that it is unconditionally secure. This protocol is feasible with present-day techniques.

Experimental Demonstration of Quantum Source Coding

We report an experimental demonstration of Schumacher's quantum noiseless coding theorem. Our experiment employs a sequence of single photons, each of which represents three qubits in terms of eight spatial and polarization modes. We initially prepare each photon in one of a set of eight nonorthogonal code word states corresponding to the value of a block of three binary letters. We use quantum coding to compress this quantum data into a two-qubit quantum channel and then uncompress the two-qubit channel to restore the original data with a fidelity approaching the theoretical limit.