Abstract:The error of a Minimal Leak Proof Protocol is analyzed and a corrected proof pro tocol is proposed. Also the security of the protocol is considered.

Abstract:How to construct a parallel cryptographic system is an important issue which nee ds to be considered. In this direction people may have a new way to build a cryp tosystem different from the traditional cryptography. In this paper, the author analyzed the differences between serial and parallel environments, and the featu res of parallel environment. Based upon the computational complexity theory, the basic theory and requirements for building parallel cryptographic systems are p resented.

Abstract:A truncated differential-linear cryptanalysis method is proposed, which extends differential-linear method. DES (data encryption standard) algorithms of 9-ro und and 11-round were analyzed. The method was proved more convenient and widel y applicable. In DES like cipher algorithms, the fact that the order in which S -boxes were placed would affect the security of cipher was shown by the method. In this way, the truncated differential-linear method gives a criterion for or dering S-boxes optimally.

Abstract:S-boxes are the only nonlinear component in many algorithms for encryption, int ension of which decides the security strength of the whole algorithm. By theoret ical analysis and statistics, there is evidence showing that large S-boxes hav e better cryptographic properties than small S-boxes. But they are harder to de sign and to implement. Now the 8×8 S-box is popular. In this paper, a method f or constructing the 8×8 S-box and 8×6 S-box based on m-sequence is describe d. Through testing, some S-boxes with better nonlinearity and better difference uniformity are obtained. Finally some 4×4 S-boxes based on orthomorphic permu tation are designed. These S-boxes offer the nonlinear resouce for further desi gn of cryptographic algorithms.

Abstract:In this paper, an elliptic curve signature scheme is proposed. This scheme is m ore efficient than ECDSA (elliptic curve digital signature algorithm) and Schnor r scheme. In addition, an implicitly-certified identity-based public key agree ment is also provided.

Abstract:In this paper, the authors construct the probabilistic model of output sequences of the stop-and-go generator, and discuss the distribution, independency, exp ected value and variance of the random variables composed by this kind of sequen ces. It is proved that these random variables are strong stationary and α- mixing random sequences, and these sequences obey the central limit theorem.

Abstract:The framework model proposed in this paper is a real time intrusion detection sy stem based on Agent, which provides an interface for intrusion detection com pone nts. Such interface can be used to detect intrusion behaviors based on both netw ork and hosts. According to the different system or network usage patterns and e nvironment diversity, a set of various agents will be created which cooperate to detect the anomalous aspects. The proposed model is an open system, which h as g ood scalability. It is easy to add new cooperating hosts and agents and to expan d new intrusion patterns. agents work in a concurrent way without any central co ntrolling module. The cooperation among Agents is implemented just by communicat ion. Agents are independent but are capable of communicating with each other whe n they take their actions. The state-checking and policy of authentication mech anism ensure the security of the agents themselves and the communication among t hem. This model is independent of specific application environment, thus providi ng a general-purpose framework for intrusion detection systems.

Abstract:The realization of MAC (mandatory access control) in role-based protection syst em is discussed. First, the definition of role and the application in security a re discussed. Then the concept of MAC is introduced and a scheme of role-based protection which realizes MAC is developed, by viewing each of the role contexts as an independent security-level and imposing non-cyclic information flow req uirement.

Abstract:Threshold group signature is an important kind of signatures, but all of the exi sting threshold group schemes have weaknesses. Several properties are proposed t o define a good threshold group scheme. Then, the weaknesses of three threshold group schemes are analyzed. The most serious weakness is that part of members ca n conspire to get system secret parameters and then forge a valid signature. In the worst situation, the total system is broken.

Abstract:In this paper, a modified Rabin signature scheme is presented based on quadratic residue problem. The main advantage of the modified scheme is simpler to descri be and more efficient to implement, there is no limitation or plain test space, especially only one modular multiplication is required for verification, and it is secure against chosen-ciphertext attack.

Abstract:In this paper, a new non-repudiation protocol is presented based on the correct ion of an existing protocol which has some security flaws. This scheme can work on an insecure and unreliable communication channel. Besides, it can deal with c heating. Some new notions and approaches for extending the SVO logic are introdu ced, then the extended SVO logic is used to analyze the new protocol and prove i ts correctness.

Abstract:Generation of two-party shared RSA keys is an important cryptographic protocol. The protocol is applied in key escrow and has a number of other important appli cations. N.Gilboa presented a protocol of two-party shared RSA key generation. The protocol is efficient, but it cannot preclude either party from active cheat ing. Based on that protocol, a new protocol of two-party shared RSA key generat ion is presented against cheater.

Abstract:It is an important and hard problem in the area of computer network security to analyze cryptographic protocols. A methodology is presented using a model checke r of formal methods, SMV (symbolic model verifier), to analyze the well known Ne edham-Schroeder Public-Key Protocol. The SMV is used to discover an attack upo n the protocol, which has never been discovered by BAN logic. Finally, the proto col is adapted, and then the SMV is used to show that the new protocol is secure.

Abstract:In this paper, it is demonstrated that the logic tool used in agent formalized d epiction should be the mixed modal logic which has both normal and non-normal m odal operators. Then a logic system A-BI is built for Agent-BDI logic and its semantics and axiom system are discussed. Especially for non-normal modal opera tors a new semantic interpretation based on Kripke's normal possible worlds is p resented. It is proved that A-BI logic system is sound and complete. A-BI logi c appropriately depicts the essence and relation of belief and intension, and ca n be used as logic tool in formalized research on agent.

Abstract:Automatic recognition of handwritten Chinese shorthand is a special issue of cha racter recognition subject. There is little literature on this subject. This pap er implements an on-line recognition system for HCSRS (handwritten Chinese shor thand recognition system) and provide experimental results for the recognition o f basic phonetic shorthands, shortforms, and linking shorthands. In this system, a structural recognition strategy based on the primitives of initial consonant symbol and rhyme symbol is applied. For efficient segmentation of primitives, a novel STSA (self-tuning segmentation algorithm) based on the segmentation-anal ysis-interaction configuration and corresponding knowledge sources is presented in this paper, which greatly improves the performance of the system. Theoretica l analysis and experimental results show that it is feasible to realize the simu ltaneous transformation from handwritten Chinese shorthands to written Chinese c haracters through computer.

Abstract:The planar offset curve cannot be expressed as rational parametric curve in gene ral excepta few types of curves such as line, arc, Hodograghs etc. In practice, the offset curve usually is approximated by lower degree rational polynomial cur ve in order to have the unified expression of data structure and geometric algor ithm in the commercial modeling systems. In this paper, an approximation approac h to NURBS (non-uniform rational B-spline) curve and its offset is presented b y using biarc. The biarc approximation of offset curve is simplified to biarc ap proximation to original curve. Some important and key problems, such as the reas onable selection of split points in NURBS curve, the definition of cotangent poi nt of biarc and error estimate method, are discussed. Examples verify the effici ency and reliability of the algorithms, which are implemented in the commercial geometric modeling systems Gems5.0 developed by CAD Center of Tsinghua University.

Abstract:Techniques for adaptive quality of services can efficiently respond to the netwo rk environments varying with time. In this paper, the QoS level-based max-min fair split-level bandwidth adaptation model is presented, which is built on a split-level adaptation control scheme that operates at the application and netw ork levels. The network uses a resource probing protocol to achieve QoS level-b ased max-min fair bandwidth allocation, while applications realize application -specific adaptive services

Abstract:Multi-Agent systems (MAS) generally exhibit complicated dynamic structure and b ehavior characteristics. If traditional architecture description languages (ADLs ) are applied, semantic gap and expression problems are difficult to overcome. A n agent-based architecture description language A-ADL is proposed in this pape r, which takes computation/connector agent as architectural elements instead of component/connector in traditional ADL. By introducing architectural primitives, rule-based agent description and multi-view mechanism, it can be effectively used to model complicated dynamic architectures and overcome semantic gap mentio ned above. This paper also describes dynamic architecture modeling method of A- ADL in detail with an example, and justifies the suitability of A-ADL for MAS b y comparing A-ADL with several other traditional ADLs.

Abstract:As an important property of ORDBMS, inheritance provides powerful capability for incremental modeling of composite objects. It also makes the DSM (dynamic schem a modification) more complex. In this paper, the semantics of full inheritance i s subdivided, and a criterion model of DSM in ORDBMS is presented. With Inherita nce Hierarchy Selective Expression, the cascade strategy or migrate strategy use d on subclasses can be chosen freely when the schema of their super classes is m odified.

Abstract:In this paper, a new fuzzy-logic approach is presented for character preclassif ication which gives a precise calculation method for the baseline detection algo rithm with tolerance analysis through analyzing the typographical structure of t extual blocks. Other virtual reference lines are extracted with clustering techn ique. In order to ensure correct character preclassification, a fuzzy-logic app roach is used to assign a membership to each typographical category for ambiguou s classes. The results prove that the proposed fuzzy typographical analysis for character preclassification is able to process to more than 10000 characters per second on a SUN 4/490 workstation and the method has been tested for different font sizes and different types with satisfaction.

Abstract:In this paper, the concept of space-mesh-surface distance is introduced. Base d on the space-mesh-surface distance, two kinds of interpolation surfaces defi ned on space-mesh-surface of triangulation are constructed. They are space-me sh-surface distance based radial basis function interpolation surface and Krigi ng interpolation surface. The infinite smoothness of the surface is discussed fo r those points that have unique distance path on space-mesh-surface. An algori thm for computing space-mesh-surface distance, named broken line tracing metho d, is given. As a whole interpolation surface, they are well in consistence with the space-mesh-surface in shapes and are suitable to be applied in local shap e estimation, such as gradient and direction estimations.

Abstract:Planar dictionary signature method which supports the physical optimization of o bject-oriented query is proposed in this paper. The basic design idea of the pr oposed method is introduced firstly. After the definition of planar dictionary a nd its data structure, the construction algorithm for planar dictionary signatur e and the query operation algorithms are proposed. Finally, the storage cost and the query cost models are constructed.

Abstract:PLC control system for sulphonation process shows the superiority of PLC over ot her kind of computer process control. It does not need the operator to press the button and turn the valve to control the temperature and regulate the velocity of sulphuric acid. In this paper, the connection method of PLC analogue expansio n I/O unit is presented, and the collection, computing, processing, control of a nalogue data and relevant programs in the system are also presented. The method of fuzzy logic switch control presented in the paper is economical, efficacious and reliable in practice.