Niu Xin-xin

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).

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.

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.

Steganalysis of LSB Matching in Gray Images Based on Regional Correlation Analysis

LSB matching improves the security of hidden message through changing the pixel’s LSB randomly, which breaks the rules of pairs of values in LSB replacement. This paper proposed a new steganalysis technique which aims at LSB matching embedding based on the local area’s correlation in grayscale images. The detection method defines the correlation between regional pixels as the difference between the sum of 8-neighbor pixels and the central pixel. The existence of embedded information can be detected by observing the change of the regional correlation before and after embedding. Compared with the existing algorithms, the advantages of the proposed method includes simplicity, computational efficiency and low false positive rate. The detection achieves high reliability when embedding rate is above 30%.

Trust Propagation Policy for Secure Interoperability in Multi-domain Environments

Access control is one of the most important issues of secure interoperability between domains. Role-based access control (RBAC) is a technology that has been proposed as an alternative approach to traditional access control mechanisms both to simplify the task of access control administration and to directly support function-based access control. This model maps users to roles and roles to permissions, making policy authorization simplified since the amount of roles are much fewer than users. Role hierarchies are the RBAC relevant extensions and they also are instrumental in reducing the complexity of role and authorization specification. In this paper, a framework for a multi-domain environment where RBAC policies have been employed is provided. Then, the theory of Hierarchical RBAC and modeling Hierarchical RBAC using role graphs are discussed in detail. Finally, role hierarchy governing read and write access to objects are studied via an example.

ID-Based Multi-proxy Sequential Signature System from Bilinear Pairing

We propose a new identity based multi-proxy signature system. Compared with the previous some ones, we firstly implement one original signer authorizing a group of persons, called proxy signers, sequentially to make signature on behalf of original signer. Also, the system combines the properly of the identity based signature, and has much more advantages that the traditional multi-proxy signature schemes without the identity based characteristic. The protocol can stop to perform in any one proxy signer. At that time, this proxy signers signature is a valid signature too.

A New Way to Construct Pseudorandom Sequence

Hyperchaos sequence has better security compared with low-dimensional chaos system. The new algorithm is proposed that hyperchaos system is applied to design the pseudorandom sequence after decreasing its dimension, then the analysis experiments are carried on to test hyperchaos sequences capability. Study shows that the new chaos pseudorandom sequence has better complexity and randomidty.