In this paper,a novel quantum steganography protocol based on Brown entangled states is proposed.The new protocol adopts the CNOT operation to achieve the transmission of secret information by the best use of the characteristics of entangled states.Comparing with the previous quantum steganography algorithms,the new protocol focuses on its anti-noise capability for the phase-flip noise,which proved its good security resisting on quantum noise.Furthermore,the covert communication of secret information in the quantum secure direct communication channel would not affect the normal information transmission process due to the new protocol’s good imperceptibility.If the number of Brown states transmitted in carrier protocol is many enough,the imperceptibility of the secret channel can be further enhanced.In aspect of capacity,the new protocol can further expand its capacity by combining with other quantum steganography protocols.Due to that the proposed protocol does not require the participation of the classic channel when it implements the transmission of secret information,any additional information leakage will not be caused for the new algorithm with good security.The detailed theoretical analysis proves that the new protocol can own good performance on imperceptibility,capacity and security.
In the field of quantum communication,quantum steganography is an important branch of quantum information hiding.In a realistic quantum communication system,quantum noises are unavoidable and will seriously impact the safety and reliability of the quantum steganographic system.Therefore,it is very important to analyze the influence of noise on the quantum steganography protocol and how to reduce the effect of noise.This paper takes the quantum steganography protocol proposed in 2010 as an example to analyze the effects of noises on information qubits and secret message qubits in the four primary quantum noise environments.The results show that when the noise factor of one quantum channel noise is known,the size of the noise factor of the other quantum channel can be adjusted accordingly,such as artificially applying noise,so that the influence of noises on the protocol is minimized.In addition,this paper also proposes a method of improving the efficiency of the steganographic protocol in a noisy environment.
The rapid development of network technology and its evolution toward heterogeneous networks has increased the demand to support automatic monitoring and the management of heterogeneous wireless communication networks.This paper presents a multilevel pattern mining architecture to support automatic network management by discovering interesting patterns from telecom network monitoring data.This architecture leverages and combines existing frequent itemset discovery over data streams,association rule deduction,frequent sequential pattern mining,and frequent temporal pattern mining techniques while also making use of distributed processing platforms to achieve high-volume throughput.
Zhiguo QuJohn KeeneySebastian RobitzschFaisal ZamanXiaojun Wang
Novel schemes are put forward to execute the joint remote preparation of an arbitrary two-qubit state with a pas- sive receiver via EPR pairs as the entangled channel. Compared with the previous protocols, the required multi-particle measurement is simplified and the classical communication cost is reduced. When the number of senders increases, the advantage is more evident. It means that the proposed schemes are more efficient in practice.
The application of χ state are investigated in remote state preparation （RSP）. By constructing useful measurement bases with the aid of Hurwitz matrix equation, we propose several RSP schemes of arbitrary two- and three-qubit states via the χ state as the entangled resource. It is shown that the original state can be successfully prepared with the probability 100% and 50% for real coefficients and complex coefficients, respectively. For the latter case, the special ensembles with unit success probability are discussed by the permutation group. It is worth mentioning that the novel measurement bases have no restrictions on the coefficients of the prepared state, which means that the proposed schemes are more applicable.
Two deterministic schemes are proposed to realize the assisted clone of an unknown four-particle entangled cluster- type state. The schemes include two stages. The first stage requires teleportation via maximal entanglement as the quantum channel. In the second stages of the protocols, two novel sets of mutually orthogonal basis vectors are constructed, With the assistance of the preparer through a four-particle or two-step two-particle projective measurement under these bases, the perfect copy of an original state can be produced. Comparing with the previous protocols which produce the unknown state and its orthogonal complement state at the site of the sender, the proposed schemes generate the unknown state deterministically.
A universal entangler is a very powerful fault-tolerant entangling device for generating quantum entanglements from any joint states. Our paper aims to address the construction of universal entanglers. We prove that universal entanglers may be obtained from random unitary gates according to the Harr measure. The success probability is close to 1 for large system spaces. This result represents the typical density of entanglement subspaces in large state spaces. It also partially solves an open problem of universal bipartite entanglers and is explained by some experiment simulations.
WANG FengLUO MingXingCHEN XiuBoYANG YiXianWANG XiaoJun
As one of essential multimedia in quantum networks, the copyright protection of quantum audio has gradually be- come an important issue in the domain of quantum information hiding in the decades. In this paper, an improved quantum watermarking algorithm based on quantum audio by using least significant qubit （LSQb） modification is proposed. Com- pared with the previous achievements, it can effectively improve the robustness and security of watermark for copyright protection of quantum audio. In the new algorithm, the least significant bites and the peripheral least significant bits of the amplitudes are modified in terms of their logical consistency and correlation to enhance watermark robustness of resisting various illegal attacks. Furthermore, the new algorithm can avoid the weak robustness defect of many previous algorithms that directly embedded the watermark into the least significant bits. In order to implement the new algorithm, some spe- cific quantum circuits are designed to obtain better applicability and scalability for embedding and extracting watermark. Finally, the simulation results including the values of audio waveforms and signal to noise ratios （SNR） prove that the new algorithm has good transparency, robustness, and security.
