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A fuzzy set-based evaluation approach is demonstrated to assess the security risks for Internet-banking System. The Internet-banking system is semi-formally described using Unified Modeling Language (UML) to specify the behavior and state of the system on the base of analyzing the existing qualitative risk assessment methods. And a quantitative method based on fuzzy set is used to measure security risks of the system. A case study was performed on the WEB server of the Internet-banking System using fuzzy-set based assessment algorithm to quantitatively compute the security risk severity. The numeric result also provides a method to decide the most critical component which should arouse the system administrator enough attention to take the appropriate security measure or controls to alleviate the risk severity. The experiments show this method can be used to quantify the security properties for the Internet-banking System in practice.

While studying the Differential Power Analysis of the DES, we've found the 4th S-Box collision phenomenon which results in fatal weak point in the DPA of the DES and makes the analysis correct rate below 50 percent. In this paper, we give the corresponding solution combating with such phenomenon and the experimental result shows that it's satisfactory.

Hierarchical tree structure is usually used for key management in complex information system. Differ- ent vertexes of the tree denote different security classes with distinct secret keys. Users in superior class can be allowed to decrypt the message belonging to the subordinating class. Commonly, the assigned key for a user needs to be changed in a period time. So it is a good solution to associate keys with time period. In this paper, we propose a new time-bound key man- agement scheme for hierarchy tree. Our scheme is very efficient because we still only use hash function in the key derivation and public information compu- tation process, and it is also secure under the existed attacks. Keywords: Cryptography, hierarchical, key manage- ment, time-bound, hash function

Ring signature is proved very useful in various applications for its perfect properties. However, the existing schemes based on the discrete logarithm are not perfect in signature and signer verification. In this paper, we introduce a new verifiable ring signature scheme based on Nyberg-Rueppel signature. The scheme realizes the ring signature using the hash functioning merely, which can verify the actual signer besides satisfying the basic properties of ring signature: unconditional anonymity and non-forgeability. The comparison shows that our signature scheme is of less size of signature and computation, and the signer verification is more simple and easy to understand

By expanding the definition of Chebyshev polynomials, the Chebyshev polynomials over finite field FP are formed. After analyzing the system of Chebyshev polynomials over finite field FP , this paper presents that the system is a divergent system and all curves of Tn(x) at n>1 are pseudo-random sequences when P is enough large. For the pseudo-random property and expand of definition of Chebyshev polynomials, Tn(x) is a good one-way function over FP. Using one-way and semi-group properties, a novel public key encryption algorithm is presented. The running of the algorithm doesn't need large prime numbers and primitive elements, but integer number

Market efficiency and unbiasedness tests are performed for the first time for three forest commodity futures markets: softwood lumber, oriented strand board (OSB), and northern bleached softwood kraft pulp (NBSK). The Johansen cointegration procedure is applied to test long-term market efficiency, while the standard error correction models (ECM) and ECM with GQARCH-in-mean process are also used to examine short-term market efficiency and unbiasedness. Results show that these markets are inefficient and biased in both the long-term and short-term. Results also indicate that no short-term time-varying risk premiums are found in these commodity futures markets.