- EI核心期刊
The scheme OTkn developed by Cheng-kang Chu and Wen-Guey Tzeng was thought of more efficiency in the congeneric protocols. A non- interactive k -out-of-n oblivious transfer protocol OTkn is presented, improved with the scheme of Chu and Tzeng. In the proposed protocol, the sender S sends O(n) messages to a receiver R, but R does not send any messages back to S. In other words, R is non-interactive with S. This scheme is proved to be more efficient than that developed by Chu and Tzeng. The receiver’s choices are unconditionally secure. The secrecy of the sender’s unchosen messages is guaranteed if the Decisional Diffie-Hellman problem is hard. The security proof of the proposed protocol has also consummated. An example of oblivious transfer protocols’ application such as a private transaction mechanism of digital productions is presented by employing the proposed scheme. The problems when all productions are different prices have been solved.
A new blind equalizer based on structure risk minimum (SRM) rule is presented. According to the feature reconstruction of signals, the method constructs the time decorrelation cost function under SRM rule, and traces channel using static iterative learning algorithm. Simulation is carried out to compare it with least mean square-based blind equalizer (LMS-BE) and neural networks-based blind equalizer (NN-BE), and the results show the method has much better performance.
The displacement analysis of a non-planar nine-link Barranov truss is completed by using Dixon resultants together with Sylvester resultant. Firstly, four geometric loop equations are set up by using vector method in complex number fields. Secondly, three constraint equations are used to construct the Dixon resultants, it is a 6×6 matrix and contains two variables to be eliminated. Extraction of the greatest common divisor（GCD）of two rows of Dixon matrix and computation of its determinant to obtain a new equation are given. This equation together with the forth constraint equation can be used to construct a Sylvester resultant. A high-order univariate polynomial equationis obtained from determinant of Sylvester resultant. During using Sylvester resultant, the different degree of high-order univariate polynomial equation is obtained because the different variable is eliminated, which leads to extraneous roots. The reason of extraneous roots is analysed and the improved method is given. After that a 50 degree univariate polynomial equation can be obtained. Other variables can be computed by euclidean algorithm and Gaussian elimination. The closed form solution of this kind of Barranov truss is obtained. At last a numerical example confirms that analytical solutions of the Barranov truss are 50.
A new identity-based partially blind signature scheme was proposed. Assuming the intractability of the q-Strong Diffie-Hellman problem, the scheme was proved to be unforgeable in the random oracle model. Compared with other existing schemes, the new scheme performs more efficient in computation because it doesn’t need inefficient MapToPoint hash function and only needs one pairing computation. Based on the scheme mentioned above, a restrictive partially blind signature is proposed and proved to be efficient, correct, unforgeable, as well as restrictive and partially blind.
A new proposal for multipoint rotate-vector optimization is presented based on the basic rotate-vector method. Some measures are adopted as increasing diversity of initial points, introducing rejection threshold and retained coefficient, then the capacity of global optimization and computational efficiency are improved by solving the examples. Genetic algorithm is compared with this method from points of view of result of example and principle of algorithm. The influence of every parameter is analyzed on the computational accuracy and time of multipoint rotate-vector method. The directory evaluation is given which is helpful to parameter setting in practical application.
In order to reduce the limits in topology inference of one parameter, a multiple parameters network topology inference method, combining end to end delay and loss, was proposed. When applying the multiple parameters based network topology inference, no additional traffic was needed; the inference method can be applied in complex networks of different loads. The multiple parameters based inference method was analyzed theoretically and validated through simulations by network simulator, version 2 (NS2). The results of simulation illustrated that the multiple parameters based inference method could infer network topology correctly when faced with different loaded networks.
A buffer allocation algorithm for wormhole routing networks-on-chip was proposed. When the total budget of the available buffering space is fixed, the proposed algorithm automatically will, according to the traffic characteristics of the target application, assign the buffer depth for each input channel in different routers across the chip. The simulation results show that the buffer allocation result is more reasonable and smaller average packet latency can be achieved compared to the uniform buffer allocation. For hotspot traffic, about 17% savings in buffering resources can be achieved using our algorithm.
A method named preference ontology denotation by decomposed attributes (PODDA) was put forward to apply preference description to the dynamic services composition. This method added semantics to the service-preference of the user and decomposed this preference into many sub preference set or attribute preference set. By abstracting sub preference set from the relations of the domain ontology’s concepts and services’ attribute preference set from the relations between the concepts, the building of the relevant ontology could better utilize the existing resource in domain ontology and express the user’s preference under multiple restrictions more profoundly. The test result of the simulation system showed that after the preference ontology based PODDA was applied the satisfaction of composition service has been greatly increased.
Considering that the trajectory and the stance of frog jump movement are the basis of the research on the biological jumping mechanism of biomimetic robot design, a new method of trajectory extraction from animal’s movement is presented. With the help of the proposal, views from both sides or from the top of the frog moving can be captured simultaneously. And the 3D information was obtained after the correction for the perspective effect and the reduction of error produced by coefficient. To overcome the shortcoming of large amount of calculation, a program is designed to deal with the video images. And finally the curve of the position, the velocity and the acceleration of each point and the angle of each joint of frog are exported. The results of experiment and analysis show that the new method could be employed to develop and control a jumping robot.
Based on the Dai’s scheme, by the revision of proxy private key structure, and addition of the public key information of verifier in the proxy authorized certificate, it is proposed that a new digital signature scheme. The scheme has two properties: (1) Strong unforgetability, original signer cannot forge a signature signed by proxy signer; (2) Misuse, proxy signer cannot complete to verify and receive he/she make a designated receiver proxy signature, and use the signature for other usage. In the same time, Multiple receiver for a signature can be designated in our scheme, during making a designated receiver proxy signature, proxy signer need interact with receiver to complete the signature, and the signature can only be received this receiver. The new scheme has high controllability.
The statistical characteristic of orthogonal frequency division multiplexing(OFDM) frequency domain channel is analyzed at first. Aiming at the peculiarity of high-speed mobile and transmitting of OFDM signal, a finite-state Markov channel model (FSMM)is formed to represent OFDM frequency domain channel which is modeled as Nakagami-m fading distribution random process that is used in modeling mobile channel more and more widely. The methodology is developed and analyzed to partition the received signal-to-noise ratio into a finite number of states according to the same duration of each state. The method of computing the duration, the threshold , the number of states and the transition probability as well as the average error probability of state is given and the close solution when m is equal to 0.5 or 1 or 2.This model can provide the good base of adaptive modulation and coding and automatic repeat request as well as dynamic resource allocation. The computation results is according to computer simulation results, which verify the accuracy of the model.
A new identity-based partially blind signature scheme was proposed. Assuming the intractability of the q-Strong Diffie-Hellman problem, the scheme was proved to be unforgeable in the random oracle model. Compared with other existing schemes, the new scheme performs more efficient in computation because it doesn’t need inefficient MapToPoint hash function and only needs one pairing computation. Based on the scheme mentioned above, a restrictive partially blind signature is proposed and proved to be efficient, correct, unforgeable, as well as restrictive and partially blind.
Abstracts network into a two-tuple containing hierarchical nodes and horizontal links. Variables of protocol entities from each layer are combined to represent three types of network states: Secure, Error and Fail-ure. The causality between vulnerabilities and network failures are described, and the dependency relationship between the finding, verifying and correlating of vulnerabilities is analyzed. A quantitative method for measuring network vulnerability is proposed and vulnerability from a theoretical perspective is as well analyzed. Finally, three solutions to lower security risks are presented.
Some properties of the stream cipher based on single cycle T-function is investigated with respected to single cycle T-function’s special properties. And also the period, linear complexity and k-error linear complexity of the sequences which are constituted by the first bits of all single word single cycle T-functions are obtained. For some words single cycle T-function, the period, linear complexity and k-error linear complexity of the sequences which are constituted by the some bit and that of the sequences constituted by the first bits in the consecutive states are given respectively. The results give that the output sequences of the single cycle T-function have good properties.
A subpixel matching algorithm for curve correspondences from images is presented. Firstly, the image curve is discretized as the pixel points. Then the initial point correspondences on the correspondence curves between the different images are performed by dynamic programming. At last, the precise point correspondences on the correspondence curves between the different images are implemented by using the conjugate gradient based on the initial matching. Compared to previous methods, the reconstruction precision is improved since the manual matching between different images is not involved by self-automatic precise extracting the curves. Experiments show that the reprojection error is remarkably reduced by the presented algorithm.
An Identity-based encryption (IBE) private key issuing protocol based on attestation identity certificate was proposed to resolve the security problem of user private key issued such as user identity authentication in private issuing, the private security transmitting and the private escrow. The proposed scheme verifies a user’s identity by trust authority (TA) issuing attestation identity certificate, uses a simple blinding technique to eliminate the secure channel and multiple authorities approach to avoid the key escrow problem. Moreover, the scheme saves at least 2t operations in comparison to Lee B et al’s protocol.
Applied to face detection, although AdaBoost is one of effective algorithms, it has some limitations. A neighbor-eliminated boosting(NEB) algorithm is proposed to remedy these deficiencies, which is like that the cascaded stage classifiers may unbalance on false reject rate and false accept rate, and that the invalidation of monotonicity assumption may conduce to abortive feature learning. NEB constructs a group of new feature describers linked by two lists, which will lead to correlation of features to simplify training. Experiments demonstrate that NEB algorithm accelerates the training speed and obtain the better performance.
Considering the characteristics of heterogeneous cooperative relay channel, the uplink and downlink relay channel models are presented. Analysis on the capacity of the heterogeneous cooperative relay channel is given, and compared with homogenous cooperative relay channel, in order to elaborate the advantages and disadvantages of the two different relay channels, as well as the applicable scene. A numerical example is given to describe how the power distribution and the location of the relay impact on the capacity of the relay channel. The differences between the two different relay channels are analyzed.
Firstly, after analyzing the generation and the distribution of the inherent error of overlap-cut (OC) method frequency domain equalization (FDE), the improved version of OC method called adaptive OC (AOC) method was proposed. Secondly, one parallel interference cancellation (PIC) structure based on non-linear feedback was designed. After nonlinear processing, the users’ feedback information during the PIC iteration was adjusted according to confidence. As a result of both analysis and simulation, AOC Method FDE outperforms the original OC Method with lower complexity. The non-linear feedback PIC further improves the performance of the receiver.
The symmetric capacity of slowly fading channels with quantized channel side information (CSI) is investigated. Optimal quantization schemes under different power constraints are derived. Without any power adaptation, the problem becomes a typical one dimension maximum problem. With power control, the optimal power control is pulse like and the optimal solution can be achieved by an iterative fashion. Numerical results show that the 4bits optimal quantization can achieve most of the symmetric capacity with perfect CSI. Besides, different from the Gaussian input results, the symmetric capacity gains of power adaptation are also obvious. For example, with the same quantization level, power adaptation brings about 10% capacity improvements.
Abstract: The investigation object is Internet-based card-not-present（CNP） payment system using Europay, MasterCard and Visa（EMV）cards. The advantages and disadvantages of several existed payment protocols based on Internet are analyzed. Computers with trusted platform modules are introduced to emulate EMV smart cards and the interface devices for use in Internet-based CNP transactions, then, a payment system project using direct anonymous Attestation technology is put forward. This project resolves obstacles that CNP transaction is up against.
As for the execution of dynamic resource allocation and pricing, the theory of non-complete information is applied to model the interaction between the service provider and the user. The proof of the existence and uniqueness of Bayes Equilibrium in theory presents that using this model, the service provider could reach the optimal pricing policy, while the user could reach the optimal selection of the bandwidth purchased. Based on the proposed model, a network resource allocation and pricing algorithm based on user demand intensity is designed. The simulation shows that it could enhance the performance of the resource utility efficiency and the whole social interest, compared with the static resource allocation method with single pricing.
Based on network coding, a method for constructing codes in multicast networks with link failure is proposed. More specifically, disjoint paths ( is larger than the multicast rate so that multicast transmissions can work well even at most link failures occur) are selected for each receiver, and the global coding vectors of any input links should be linearly independent. Then the receivers can obtain right symbols, and avoid link failure. By using some results available of MDS codes, the minimal finite field which is enough to implement network coding for different multicast rate is obtained. To design codes of multicast network and implement network coding, a generator matrix of a maximum distance separable（MDS） code is constructed based on the obtained minimal finite field, and its column vectors are allocated to input links of receivers as their coding vectors.
Under the constraints of interference temperature and total transmit power, an algorithm is proposed for the uplink in orthogonal frequency division multiple access（OFDMA）based cognitive radio networks to maximize the system throughput. With the algorithm, the initial allocation will be adjusted to achieve the optimal allocation step by step. The simulations show that the proposed algorithm achieves the performance of exhausted scheme while decreasing the computational complexity largely.
We propose a new method for error correction coding based on shape preserving characteristic of the phase-only transform. It creates 2 descriptions by phase mapping and pixel interleaving。It synthesizes the image with only a little distortion by phases and damaged magnitudes. The receiver decodes a high quality image when both descriptions are received. Images, badly damaged due to the high error rate in transmission, can also be recovered from the only available description with an acceptable quality. Simulations show that it outperforms schemes such as pixel interleaving and phase scrambling by about 1.5~3 dB in peak signal to noise ratio (PSNR).
A scheme of subcarrier-bit allocation is proposed for the power optimization in multiuser orthogonal frequency division multiplexing（OFDM） system. The scheme allocates the subcarriers to reduce the power of users with the principle of Min-Max, allocates the bit by water-filling to minimize the power of users. Finally the bit is rounded by greedy algorithm to obtain the minimized total transmit power of the system. Theoretical analysis and simulation results show that the performance is improved but with low complexity.
An opportunistic cooperative network-coding scheme based on space-time coding (OCNC) is proposed for combining channel fading and improving resource efficiency and network throughput. Focusing on the bi-directional traffic flows in wireless cooperative relaying network, the OCNC schemes, termed as 3-step and 2-step schemes respectively is grouped, and their bit error probabilities and the network-coding gain is developed and analyzed. The numerical results show that, in contrast to traditional scheme, a full diversity (i.e. K-order diversity in case of K relay nodes) is achieved by both OCNC schemes and asymptotical 4/3 and 2 times of network-coding gain are obtained by 3-step and 2-step OCNC schemes respectively. In addition, because of opportunistic relaying of multiple nodes, the network-coding gain of OCNC is more considerable in the medium signal-to-noise ratio (SNR) range.
Two new methods for constructing zero correlation zone (ZCZ) sequence set from an arbitrary perfect sequence and unitary matrices are presented．The key of this method is to spread a perfect sequence by correlation product of the shift sequences set of the perfect sequence and corresponding unitary matrix. The new sequence sets are approximately optimal and optimal respectively with respect to the mathematical bound by using different choice of shift sequences set of perfect sequence．
Dynamic limited polling multiple access protocol based on waiting time of packets and channel state is proposed. This protocol adaptively controls the polling process according to the instantaneous waiting time of packets and the channel state for each node, and serves the one with the longest packet waiting time and good channel state first in each polling cycle. By means of imbedded Markov chain theory and vacation queue model, the model and its performance analysis of that protocol are given assuming that channel is modeled as a two-state Markov chain. By comparing with the basic polling system, it is shown that the proposed system can reduce the mean waiting time of packets and increase system throughput.
A modified serial decoding algorithm for low-density parity-check（LDPC） codes is proposed. Unlike conventional approaches, this algorithm calculates the sum of variable-to-check messages only once at the initialization stage, and then updates it by simple recursions during the decoding stage. Compared with the conventional serial LDPC decoding algorithm, the proposed algorithm has lower computational complexity and higher processing speed without any performance deterioration.