Yang Yixian

Design of speech information hiding telephone

The speech information hiding telephone (SITH) is a new steganography scheme based on information hiding security technique system The overall system is designed in embedding method using one fixed point DSP TMS320C54x and three floating DSPs TMS320C31, and a single-chip micro-controller, all DSPs working parallel in speech processing. It is designed for secure and covert communication when speech is transmitted over a public switching telephone network (PSTN).

TM-RMRP: A Trust Model Based on a Recommendation Mechanism of Rewards and Punishments

As trust management can address the new security challenges in pervasive computing environments, we present our pervasive trust model TM-RMRP which is composed of input factors and trust evaluation. With the model presented, anonymous entities can collaborate with trustful parties without central security managers. To reduce or even avoid inappropriate or inaccurate recommendations, we introduce the concept of recommendation trust and propose a recommendation mechanism of rewards and punishments based on this concept to identify more reliable recommendations. From the simulation results, the mechanism is proved to be applicable in pervasive computing environments.

A DDoS Attack Defending Scheme Based on Network Processor

The distributed denial of service attacks have become more and more frequent and caused some fatal problems. Many researches have been done to detect and defend such attacks, however, many solutions are still in the phase of theoretical studies. Some of them may have certain practical value, but they have to reconstruct the existing network and the routing instruments with great cost. This paper proposes a DDoS attack defending scheme based on network processor. The scheme takes advantage of network processor’s powerful process ability to divide the network flow into different types firstly, and then uses a QoS mechanism to ensure essential communications as well as to eliminate the attack flow to the greatest extent. Experiment results show that the scheme can provide enough bandwidth for high priority flow, and effectively weaken the attack flow.

A Data Safety Transmission Solution in Web Application

This paper presents a design of a new data safety transmission system in web service after researching existing safety transmission resolutions. This system designs the private safety transmission protocol and the hardware board. The private safety protocol is a multi-layer structure and provides security and reliability in data transmission. The hardware board uses DSP chip to realize protocol and encryption and selects USB and EMAC as the interface of data transmission. The development of terminal software makes use of COM+ technology. It can improve the security of data transmission in web application with good transmission efficiency and quality.

On costas arrays

Costas array is a class of radar signal array with perfect correlation property. An open problem about the limiting performance of the costas array (i.e. the Golomb-Taylor’s fifth conjecture) is solved in this paper.

Security Mechanism Research of EMV2000

Comprehensive analysis on the security mechanism of EMV2000 payment protocol indicates that there is still some frangibility in EMV2000 payment systems. Based on EMV2000 transaction flow, improvement advice to enhance the security of EMV transaction protocol is put forward. The authentication information that the terminal sends to the card, the issuer sends to the terminal and the issuer sends to the card is enhanced. Then, a rigorous formal verification of the improved protocol is presented.

A Random Walk Method for Sentiment Classification

Sentiment classification is very useful in many applications such as analysis of product reviews in e-business applications and media opinion mining. In this paper, a novel method to tag words sentiment automatically is proposed. In this method, a word association graph is firstly constructed from text corpus, i.e. product reviews, in which each node is a word and if there is an edge between two words, it means the two words co-occur in the same sentence. And then, with a random walk algorithm, the sentiment score is calculated for all the words in the graph at one time. To show the effectiveness of our method, the sentiment tagging results are then used for sentiment classification on real data set. The experimental results show that the sentiment classification results with our method are better than the compared methods.

Practical hierarchical identity based signature in the standard model

Hierarchical ID-based signature (HIBS) scheme is a generalization of identity based signature. It allows a root PKG to generate private keys for domain-level PKGs, who in turn generate private keys for their users in the domains of the lower level. A practical hierarchical identity based signature scheme (HIBS) based on bilinear parings is proposed. Assuming the intractability of the computational Diffie-Hellman problem, our HIBS is unforgeable under adaptive chosen-message and ID attack in the standard model. The number of public parameters is significantly less compared to the scheme that is constructed by using Waterspsila method. We also have presented a variety of techniques to improve its space requirements and computational requirements and briefly analyzed the aggregation properties of our scheme.

An efficient bit commitment scheme based on factoring assumption

Recently, many bit commitment schemes have been presented. This paper presents a new practical bit commitment scheme based on Schnorr’s one-time knowledge proof scheme, where the use of cut-and-choose method and many random exam candidates in the protocols are replaced by a single challenge number. Therefore the proposed bit commitment scheme is more efficient and practical than the previous schemes. In addition, the security of the proposed scheme under factoring assumption is proved, thus the cryptographic basis of the proposed scheme is clarified.

On the perfect binary arrays

The close relationship between the perfect binary arrays (PBA) and the higher dimensional Hadamard matrices is initially discovered. Some very interesting results about the Fourier transform spectrum of PBA are shown and a few open problems are also pointed out in this paper.