Cryptanalysis of Full-Round Magpie Block Cipher

Magpie is a lightweight block cipher proposed by Li et al. in Acta Electronica Sinica volumn 45,issue 10. It adopts an substitution-permutation network(SPN) structure with a block size of 64 bits and the key size of 96 bits, respectively. To achieve the consistency of the encryption and decryption, which is both hardware and software friendly, 16 bits of the key are used as control signals to select S-boxes and another 16 bits of the key are used to determine the order of the operations. As the ...     

精确的转化型融合线性反馈移位寄存器

For the published block cipher algorithm, two kinds of round functions have been researched. Block ciphers in network environments are taking more risks than ever before because of their initialization key＇s distribution in the internet. The security of block cipher algorithm is affected by linear bias and nonlinear bias which are restricted by confusion layer and diffusion layer. This article takes an approach on how block cipher＇s two round structures are initially transformed when they fuse into LFSR. The SP structure can be considered two F functions in one Feistel round function which combines both right and left of origin data transformation. Furthermore, the round number linear function and nonlinear function of Feistel and SP structure are compared. The merit of SP structure is that it can fuse in LFSR as a nonlinear filter without memory.     

Impossible Differential Evaluations for New-Structure Series

Impossible differential cryptanalysis is a powerful tool to evaluate the strength of a block cipher structure, and the key step of this cryptanalysis is to find the longest impossible differential. Recently a series of generalized Feistel structures named New-structure I, II, III and IV were proposed, which were designed with full consideration of differential and linear cryptanalysis secu- rity. In this paper, we investigate the impossible differen- tial properties of New-structure series, and we show that there always exists 14/∞/19/15 rounds impossible differ- ential for New-structure I, II, III and IV respectively.     

Multiple Related-Key Diff erential Attacks on Pure DDP-Based Cipher

By constructing three types of related-key differential characteristics, we present three corresponding related-key differential attacks on the cipher. As the inde-pendence of the characteristics, we could recover 64 bits of the cipher’s m aster key with 258.6 chosen plain-texts, 258.8 full-round DDP-64 encryptions and 212.8 bits of storage re-sources. To break the cipher, we only need to implement an exhaustive search for the rest 64 bits of the m aster key.     

The research and design of reconfigurable computing for Block cipher

This paper describes a new specialized Reconfigurable Cryptographic for Block ciphers Architecture（RCBA）.Application-specific computation pipelines can be configured according to the characteristics of the block cipher processing in RCBA,which delivers high performance for cryptographic applications.RCBA adopts a coarse-grained reconfigurable architecture that mixes the appropriate amount of static configurations with dynamic configurations.RCBA has been implemented based on Altera’s FPGA,and representative algorithms of block cipher such as DES,Rijndael and RC6 have been mapped on RCBA architecture successfully.System performance has been analyzed,and from the analysis it is demonstrated that the RCBA architecture can achieve more flexibility and efficiency when compared with other implementations.     

Multi-branch query tree protocol for solving RFID tag collision problem

The technology of anti-collision is a key point in radio frequency identification （RFID） system. To avoid data collision, there are two approaches： ALOHA based algorithm and binary tree （BT） based algorithm. However, these cannot solve the collision problem completely, especially when the tag quantity is big and the tag ID is long. In this article, we present a multi-branch query tree （MBQT） protocol based on balanced incomplete block design （BIBD） code, and use 16-bit vectors derived from the BIBD as query prefix symbols of RFID reader. Compared with the conventional anti-collision algorithm, the theoretic analysis and simulation show that the proposed protocol improves the identification efficiency.     

Modelling of nanostructured TiO2-based memristors

The fourth fundamental circuit element memristor completes the missing link between charge and magnetic flux. It consists of the function of the resistor as well as memory in nonlinear fashion. The property of the memristor depends on the magnitude and direction of applied potential. This unique property makes it the primitive building block for many applications such as resistive memories, soft computing, neuromorphic systems and chaotic circuits etc. In this paper we report TiO2-based nanostructured memristor modelling. The present memristor model is constructed in MATLAB environment with consideration of the linear drift model of memristor. The result obtained from the linear drift model is well matched with earlier reported results by other research groups.     

A vector quantization based approach for CFA data compression in wireless endoscopy capsule

A novel approach for near-lossless compression of Color Filtering Array （CFA） data in wireless endoscopy capsule is proposed in this paper. The compression method is based on pre-processing and vector quantization. First, the CFA raw data are low pass filtered and rearranged during pre-processing. Then, pairs of pixels are vector quantized into macros of 9 bits by applying block partition and index mapping in succession. These macros are entropy compressed by Joint Photographic Experts Group-Lossless Standard （JPEG-LS） finally. The complex step of codeword searching in Vector Quantization （VQ） is avoided by a predefined partition rule, which is suitable for hardware implementation. By control of the pre-processor and VQ scheme, either high quality compression under unfiltered case or high ratio compression under filtered case can be realized, with the average Peak Signal-to-Noise Ratio （PSNR） more than 43dB and 37dB respectively. Compared with the state-of-the-art method and the previously proposed method, our compression approach outperforms in compression performance as well as in flexibility.     

A Low-Power dTLB Design Based on Memory Region Encoding

Translation lookaside buffers （TLBs） consume significant power due to their highly associative structure. This is getting worse with the increasing width of Virtual page number （VPN） and TLB capacity in 64- bit computing. In this paper, we present a new data TLB （dTLB） design that reduces VPN width to a large extent, thereby saving considerable power during TLB lookups. This design is motivated by an observation： the VPN can represent a much larger set of memory regions than what can be cached by the TLB at any time. We exploit this redundancy by encoding some high-order VPN bits with a shorter memory region id before the VPN is sent to dTLB. The consistency of the encoding and the recycling of memory region ids are taken cared by a small amount of hard- ware with little timing/power overhead. Experimental results on SPEC CPU2000 show a 37% energy reduction of dTLB with negligible performance penalty.     

Novel two-layer motion estimation for video coding

In this paper,we proposed a novel Two-layer Motion Estimation （TME） which searches motion vectors on two layers with partial distortion measures in order to reduce the overwhelming computational complexity of Motion Estimation （ME） in video coding.A layer is an image which is derived from the reference frame such that the sum of a block of pixels in the reference frame determines the point of a layer.It has been noticed on different video sequences that many motion vectors on the layers are the same as those searched on the reference frame.The proposed TME performs a coarse search on the first layer to identify the small region in which the best candidate block is likely to be positioned and then perform local refined search on the next layer to pick the best candidate block in the located small area.The key feature of TME is its flexibility of mixing with any fast search algorithm.Experimental results on a wide variety of video sequences show that the proposed algorithm has achieved both fast speed and good motion prediction quality when compared to well known as well as the state-of-the-art fast block matching algorithms.     

3D Freehand Tracking Based on Relevancy Among Local Motion Models

A novel 3D freehand tracking algorithm based on relevancy among local motion models is put forward. Firstly, a specification of the Cognitive and behavioral model （CBM） called PAMT is proposed. Secondly we regard PAMT as a data structure upon which freehand tracking algorithm is designed, and we describe the PAMT in detail. Lastly, the experimental results are provided. The proposed algorithm is tested in a virtual assembly platform and two other application systems. The highlights of this paper are as follows： （1） A new cognitive and behavioral model, called PAMT, is presented; （2） The PAMT is explained with cognitive model; （3） Focus on describing ＇Attractor in PAMT with the relevancy among local motion models; （4） Shows us how the PAMT is shaped and used to design the 3D freehand tracker. One of the advantages of PAMT and RLMM model is that it is easier to explore some of the complex correlations among the variables of the 3D hand model. Our experimental results show that, compared with the particle filter and the annealed particle filter, our algorithm effectively reduces dimensionality and can track 3D hand in real-time.     

Dynamic Cell Range Expansion-based Interference Coordination Scheme in Next Generation Wireless Networks

Deploying Picocell Base Station（PBS） throughout a Macrocell is a promising solution for capacity improvement in the next generation wireless networks.However,the strong received power from Macrocell Base Station（MBS） makes the areas of Picocell narrow and limits the gain of cell splitting.In this paper,we firstly propose a Dynamic Cell Range Expansion（DCRE） strategy.By expanding the coverage of the cell,we aim to balance the network load between MBS and PBS.Then,we present a cooperative Resource block and Power Allocation Scheme（coRPAS）based on DCRE.The objective of coRPAS is to decrease interference caused by MBS and Macrocell User Equipments,by which we can expand regions of Picocell User Equipments.Simulation results demonstrate the superiority of our method through comparing with other existing methods.     

Sampling adaptive block compressed sensing reconstruction algorithm for images based on edge detection

In this paper, a sampling adaptive for block compressed sensing with smooth projected Landweber based on edge detection （SA-BCS-SPL-ED） image reconstruction algorithm is presented. This algorithm takes full advantage of the characteristics of the block compressed sensing, which assigns a sampling rate depending on its texture complexity of each block. The block complexity is measured by the variance of its texture gradient, big variance with high sampling rates and small variance with low sampling rates. Meanwhile, in order to avoid over-sampling and sub-sampling, we set up the maximum sampling rate and the minimum sampling rate for each block. Through iterative algorithm, the actual sampling rate of the whole image approximately equals to the set up value. In aspects of the directional transforms, discrete cosine transform （DCT）, dual-tree discrete wavelet transform （DDWT）, discrete wavelet transform （DWT） and Contourlet （CT） are used in experiments. Experimental results show that compared to block compressed sensing with smooth projected Landweber （BCS-SPL）, the proposed algorithm is much better with simple texture images and even complicated texture images at the same sampling rate. Besides, SA-BCS-SPL-ED-DDWT is quite good for the most of images while the SA-BCS-SPL-ED-CT is likely better only for more-complicated texture images.     

A RT Steganalytic Method for Optimal Parity Assignment Algorithm

Steganography is the art of transmitting a message by embedding it into multimedia data without drawing any suspicions. OPA （Optimal parity assignment） algorithm is one of the most secure steganographlc methods for palette format images. In this paper, we present RT （Replacement transfer） steganalytic algorithm for detecting the secret messages embedded by OPA and the improved algorithm. Based on the analysis of Replacementtransfer structure （RTS） of colors, we explore the singular statistics of core colors in OPA stego-images via replacement operation. In addition, we can estimate statistics of the cover-image from the corresponding stego-lmage by an average filtering operation. With the estimation of statistics of the cover image and the singular statistics of the stego-image, the length of secret messages embedded in palette format images with OPA and the improved algorithm can be estimated. The experimental results indicate that the RT steganalytic algorithm is eiTective and accurate.     

A coding scheme using global motion estimation for AVS P-frame

Block matching has been used for motion estimation and motion compensation in the Audio and Video Standard （AVS） for years. While having an acceptable performance in describing motion between frames, it requires quite a few bits to represent the motion vectors. In certain circumstances, the use of global motion estimation and compensation would perform equally well or even better than the block matching in terms of motion accuracy, while it results in the coding of global motion model parameters. In this letter, we modify an AVS coder by adding （1） six global motion model parameters to the frame header, and （2） mode selection among INTRA, SKIP, INTER-16×16, INTER-16×8, INTER-8×16, INTER-8×8, and Global Motion Compensation （GMC） modes by Lagrange optimal rate-distortion criteria. Simulation results demonstrate that over 0.1dB improvement in PSNR is obtained compared to the AVS coder for an average coded P-frame with the same bitrate.     

LB-AGR: level-based adaptive geo-routing for underwater sensor network简

Underwater sensor network（UWSN） adopts acoustic communication with more energy-consumption and longer propagation-delay, which bring great challenges to protocol design. In this paper, we proposed level-based adaptive geo-routing（LB-AGR） protocol. LB-AGR divides traffics into four categories, and routes different types of traffic in accordance with different decisions. Packets upstream to the sink are forwarded unicast to the best next-hop instead of broadcasting to all neighbor nodes as in present UWSN routing protocols. LB-AGR defines an integrated forwarding factor for each candidate node based on available energy, density, location, and level-difference between neighbor nodes, which is used to determine the best next-hop among multiple qualified candidates. Through simulation experiments, we show the promising performance of LB-AGR.     

A molding method to fabricate the waveguide multilayer card

Waveguide multilayer optical card （WMOC） is a new kind of three-dimensional storage device. A method of fabricating the WMOC using the molding technique is introduced in this paper. The fabrication of WMOC mainly includes data writing with hot embossing method and multilayer bonding with PDMS material. The structure of the WMOC is consisted with Polycarbonate （PC） as the core layer material and Polydimethylsiloxane （PDMS） as cladding layer. The experimental results demonstrate that the molding fabrication method is feasible and effective.     

Designing a Secure Round Function Based on Chaos

A round function based on chaos is designed combining Feistel structure’s pseudo-randomness, chaotic system’s parameter sensitivity and image data characteristics. The round function composes of two parts--data transformation based on Feistel(abbreviated as FST) and sampling output based on chaos(abbreviated as SMP). FST bases on Feistel structure and several efficient operations including bitwise xor, permutation and circulating shift. SMP is a chaos based pseudo-random sampling algorithm. It is from theoretical analysis that the round function is a pseudo-random function. The upper bounds of the average maximum differential probability and average maximum linear probability are p^2 and q^2 respectively. Finally, the good pseudo-randomness of the round function is examined with the NIST random test. The design of this round function provides an important cryptographic component for the design of chaotic image encryption algorithm.     

Optimized Multicast Routing Algorithm Based on Tree Structure in MANETs

Mobile Ad hoc Networks （MANETs） play an important role in emergency communications where network needs to be constructed temporarily and quickly. Since the nodes move randomly, routing protocols must be highly effective and reliable to guarantee successful packet delivery. Based on the data delivery structure, most of the existing multicast routing protocols can be classified into two folders： tree-based and mesh-based. We observe that tree-based ones have high forwarding efficiency and low consumptions of bandwidth, and they may have poor robustness because only one link exists between two nodes. As a tree- based multicast routing protocol, MAODV （Multicast Ad hoc On-demand Vector） shows an excellent performance in lightweight ad hoc networks. As the load of network increases, QoS （Quality of Service） is degraded obviously. In this paper, we analyze the impact of network load on MAODV protocol, and propose an optimized protocol MAODV-BB （Multicast Ad hoc On-demand Vector with Backup Branches）, which improves robustness of the MAODV protocol by combining advantages of the tree structure and the mesh structure. It not only can update shorter tree branches but also construct a multicast tree with backup branches. Mathematical analysis and simulation results both demonstrate that the MAODV-BB protocol improves the network performance over conventional MAODV in heavy load ad hoc networks.