Applied Mechanics and Materials Vols. 263-266

Abstract: The function $x^{2^{n-1}-1}+ax^5 (n$ odd, $a\in\mathbb{F}_{2^n}$) is differentially 4-uniform and is never bijective. Using Hermite’s Criterion, prove some necessary conditions that $x^{2^{n-1}-1}+ax^5+L(x), L(x)$ being a permutation polynomial.

Abstract: The Bit Commitment (BC) is an important basic agreement in cryptography . The concept was first proposed by the winner of the Turing Award in 1995 ManuelBlum. Bit commitment scheme can be used to build up zero knowledge proof, verified secret sharing, throwing coins etc agreement.Simultaneously and Oblivious Transfer together constitute the basis of secure multi-party computations. Both of them are hotspots in the field of information security. We investigated unconditional secure Quantum Bit Commitment (QBC) existence. And we constructed a new bit commitment model – double prover bit commitment. The Quantum Bit Commitment Protocol can be resistant to errors caused by noise.

Abstract: The Oblivious Transfer (OT) is a typical foundation agreement of secure multi-party computations. It can be used to solve the “ Millionaire” interesting question raised by the winner of the Turing Award in 1982, Mr. Yao , thus to build more complex secure multi-party computation protocol or to solve practical problems,such as electronic voting, elections, e-commerce. Using of the quantum channel and the principles of the quantum mechanics , Quantum Oblivious Transfer (QOT) can be solve the classic oblivious transfer problems. QOT can be achieved higher security and higher efficiency than the Classic Oblivious Transfer, while it also has a unique advantage in found eavesdropping. We had given a very novel QOT scheme based on three-particle entangled states. Although the use more particles , the process is better concise.

Abstract: In this paper, the cat map and the chaotic map are analyzed, and a key variable algorithm which combines chaotic map and cat map is proposed. What’s more, a variable key encryption system processes combined with the voice preprocessing is put forward. The simulation results show that the algorithm has a good voice encryption security features.

Abstract: This paper focused on the distribution automation system of information security risk in the secondary system，analyzed distribution automation system function，structure , communication and common information security protection method，proposed security reinforcement suggestions of distribution automation system, and made the next step clearly in the research direction.

Abstract: In this paper, a novel and efficient steganalysis based on improved K-means clustering using One-Class Support Vector Machine (OC-SVM) was proposed to blindly determine the existence of hidden messages in an image. The performance of sample clustering is concerned in the OC-SVM with multi-sphere. In previous work, the K-means was mainly used to create such multi-sphere by clustering. But the traditional K-means depends on initial clustering centers and ended local minimum value. So, to improve the clustering performance of K-means, the SA is employed into the scheme, which can create more reasonable multi-sphere by finding global optimum solutions in the clustering process. Simulation results with the chosen feature set and well-known steganographic techniques indicated that our approach was able to afford reasonable accuracy to distinguish between covers and stego images.

Abstract: A robust watermarking scheme that used computer-generated holograms as the watermark is in NSCT (NonSampled Contourlet Transform) domain was proposed. To maintain imperceptibility and robustness, a repeated embedding algorithm is adopted to embed the mark hologram into the low-frequency subband of the NSCT host image. Compared with other watermark schemes using digital holograms, the proposed algorithm has the obvious advantage in robustness The experimental results demonstrated that the proposed method had good robustness to resist common attacks such as, rotation, scaling, translation, image flipping, combined attacks, filtering, occlusion, cropping, and JPEG compression.

Abstract: In this paper, a novel approach is proposed to detect JPEG image forgery based on the inconsistencies of quantization tables. The primary quantization table of tempered image is firstly estimated. Then the blocking artifact measure (BAM) of each 8×8 DCT coefficient block is computed using the estimated quantization matrix, and the BAMs of all blocks are sorted in descending order. Select a certain number of blocks of which the BAM is in the front of the order. Labeling the connected components of blocks in order to eliminate some abnormal blocks and gain the connected doctored blocks. Experimental results demonstrate the validity of the proposed approach.

Abstract: Fast data transmission put forward high requirements on network content matching (NCM). Due to the high time complexity, Nondeterministic Finite Automata (NFA) was unable to meet the demand of regular expression matching (REM) which was the core of NCM; Transfer NFA to Deterministic Finite Automaton (DFA) could enhance the throughput, but led to state explosion, which increased demand for memory. To balance memory and throughput, state explosion in the transformation from NFA to DFA has been analyzed and a new method DC-DFA is presented for large scale REM. DC-DFA is based on hybrid automata structure which composed of NFA and DFA. DC-DFA introduces GradeOne classification to cut the memory usage and deep classification to improve throughput. The results show that for serious state explosion, DC-DFA could reduce 75% DFA states and improve memory utilization efficiently while maintain high system throughput.

Abstract: The safety of the six-state scheme in the practical communication systems was studied based on an effective eavesdropping method, which called path attacks adopted by eavesdroppers. In the practical systems, eavesdropper can select appropriate path to eavesdrop on legitimate users to obtain some information. This method will keep photon number distribution in the laser pulses, and the eavesdropper can be hidden by the losses of quantum channel without being detected. The results show that eavesdropper can get more information with the increase of transmission distance and the average number of photons.