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Secure multiparty computation is an area of recent research in the international cryptographic community, and secure computational geometry is an essential field of secure multiparty computation. Most of the existing studies of secure multiparty computational geometric problems have focused on plane geometry, while very few have addressed solid geometry. Because solid geometry is an integral part of geometry and describes the real world better than plane geometry, research on secure computational solid geometry is appealing. Motivated by an interesting application, we first examine the problem of the secure multiparty computation of a tetrahedron, propose a solution, and prove that the solution is private using an accepted simulation paradigm. Using the solution to the tetrahedron problem as a building block, we further solve the secure multiparty computation of three other solid geometric problems, including the relationship between a point and a plane, the relationship between a line and a plane, and the relationship between two planes. We also demonstrate that the solutions to these problems are private. We analyze the computational and communication complexities of these solutions and show that the computational complexities are near or equal to the problems' minimum theoretical computational complexity and that the communication complexities are equal to the minimum theoretical communication complexity. Thus, these solutions are optimal. Finally, we show an interesting application of secure computational solid geometry.

Secure multiparty computation has become a central research focus in the international cryptographic community and in the future likely will represent an integral part of computing science. Protocols for Yao's millionaires' problem provide the building blocks for many secure multiparty computation protocols, which makes their efficiency critical. Unfortunately, all known protocols for Yao's millionaires' problem employ public key cryptography and thus are inefficient. This article constructs a new efficient solution to Yao's millionaires' problem based on symmetric cryptography. We first develop an efficient protocol for set-inclusion problems, which has independent interest for secure multiparty computations. The privacy-preserving property of the solution is demonstrated by a well-accepted simulation paradigm. To compare the security levels of different solutions, we propose a new security paradigm that quantitatively captures the security levels of different solutions and can determine which secure multiparty computation solution is preferable. This article thus provides an important supplement to the simulation paradigm. Together with the simulation paradigm, it offers a complete security evaluation benchmark for multiparty computations.

In order to provide predictable runtime performance for text categorization (TC) systems, an innovative system design method is proposed for soft real-time TC systems. An analyzable mathematical model is established to approximately describe the nonlinear and time-varying TC systems. According to this mathematical model, the feedback control theory is adopted to prove the system's stableness and zero steady state error. The experiments result shows that the error of deadline satisfied ratio in the system is kept within 4% of the desired value. And the number of classifiers can be dynamically adjusted by the system itself to save the computation resources. The proposed methodology enables the theoretical analysis and evaluation to the TC systems, leading to a high-quality and low-cost implementation approach.

Secure multi-party computation is a focus of international cryptography in recent years. Protocols for Yao's millionaires' problem have become an important building block of many secure multi-party computation protocols. Their efficiency are crucial to the efficiency of many secure multi-party computation protocols. Unfortunately, known protocols for Yao's millionaries' problem have high computational complexity or communication complexity. In this study, based on the 1-out of-m oblivious transfer and set-inclusion problem, we propose a new protocol to solve this problem. This new protocol is very efficient in terms of both computational and communication complexities. Its privacy-preserving property is also proved by simulation patadigm which is generally accepted in the study of secure multi-party computation. We also compare the information leakage of our new protocol and the known protocols.

A new elliptic curve scalar multiplication algorithm is proposed. The algorithm uses the Frobenius map on optimal extension field (OEF) and addition sequence. We introduce a new algorithm on generating addition sequence efficiently and also give some analysis about it. Based on this algorithm, a new method of computing scalar multiplication of elliptic curve over an OEF is presented. The new method is more efficient than the traditional scalar multiplication algorithms of elliptic curve over OEF. The comparisons of traditional method and the new method are also given.

The concept of generalized group signature scheme will be present. Based on the generalized secret sharing scheme proposed by Lin and Harn, a non-interactive approach is designed for realizing such generalized group signature scheme. Using the new scheme, the authorized subsets of the group in which the group member can cooperate to produce the valid signature for any message can be randomly specified.

With the increase of network complexity and continuous development of network attack techniques, it is unrealistic to prevent network from attacks or intrusion threats absolutely, a large number of critical network services require that they can provide adequate qualities of services in the face of suffering intrusions or even certain parts of network system be destroyed. Therefore, network survivability technologies in open environment are becoming a research focus in network security field. This paper proposes network threat evolution model based on threat evolutionary behaviors and threat propagations. Then, network survivability is abstracted as a dynamic game process among network attacker, network defender and normal user, thereafter network survivability stochastic game model is established and network survivability analysis algorithm is proposed based on the game model. Finally, the proposed network survivability analysis model and approach are experimented in a typical network environment. The results show that the analysis model and approach proposed are feasible and effective.

Network survivability has the characteristics of complexity, dynamic evolution and uncertainty, which has become one of the most important indicators of evaluating network performance. Network survivability evaluation is a process of confirming the degree to which the network survivability technology and mechanism can defend network threats. Firstly, it needs to extract useful information from the actual system and establish the model, then the model is analyzed and necessary information is extracted. Finally, the survivability characteristics of the network can be measured and evaluated based on the model and extracted information. Current network security research lacks of models and methods which guide network survivability evaluation effectively. In this paper, we firstly describe the elements of network survivability evaluation model and their relationships, then propose a network survivability evaluation model based on evolutionary computation which includes the immune evolutionary algorithm for network survivability metric weight solving and network survivability evaluation method based on multiple criteria decision making. Finally, the correctness and effectiveness of the proposed model is validated through experimental analysis.

National critical infrastructure is a typical complex system with the characteristics of self-organized criticality. In this paper, we firstly analyze the basic concepts of national critical infrastructure and the associated complex system characteristics, and then construct the model of national critical infrastructure based on complex system theory. This model abstracts the nodes of national critical infrastructure network and their connectivity relationships, and supports the measurements of national critical infrastructure's attributes, therefore reflects the dynamics of national critical infrastructure. The occurrence and propagation mechanism of national critical infrastructure's cascade failure behavior is analyzed based on this model, which preliminary validates effectiveness of the proposed model.

The accurate identification and effective analysis of software vulnerabilities depends on flexible and extensible analysis environment. However, current research work cannot provide highly available environment supporting for different types of vulnerabilities. Aiming at the problem, this paper proposes a novel method for constructing software vulnerability analysis environment based upon virtualization technique, defines the system level simulation model for vulnerability analysis, and describes the simulation model based vulnerability analysis method. Based upon the simulation model and analysis method, we have designed and implemented the Virtualization-based Vulnerability Analysis Environment (VirtualVAE), which can examine the operation behaviors of guest operation system and applications at hardware level, and analyze the operation process of sensitive data in the whole system. Therefore, it can accurately simulate a wide variety of system behaviors, and provide dynamic analysis capabilities for different types of vulnerabilities. The experimental results show that it provides a flexible environment for accurately identifying and analyzing the vulnerabilities of software systems.

The survivability of network is of vital importance with respect to the normal operation of information infrastructure. The current research works in the area of network survivability generally aimed at the definitions and quantifications of specific survivability attributes for distinct network objects. Unfortunately, there is a lack of research concerning how to model, measure and analyze the survivability of network in a consistent manner, and it is helpful to the unification of network survivability measurement and the promotion of related research works in the area of network survivability. Furthermore, the requirements for network survivability measurement are variable among different application domains. Therefore, a flexible mechanism to support the customizable measurement of network survivability is needed. In this paper, we propose a unified framework for network survivability measurement which is extensible and customizable. The customization method of network survivability measurement model and the process of network survivability measurement are analyzed in detail. The analysis result shows the generality and practicability of the framework.

This paper aims at the problem of software’s abuse in the computer system, and puts forward the “Software Registration” strategy in the context of enterprise networks and the computer systems within. Based on this strategy we have designed a computing system that is fit for internal use in enterprise networks by taking control of the use of computer software. The paper analyzes the system’s security and proves that the mechanism could guarantee the validity and chastity of the software in the computing system, thus greatly reduces the risk caused by software abusing. Finally, the paper prospects the future of the “Software Registration” mechanism.

This paper proposes a control flow based security analysis approach for binary executables. Through deeply investigating the theory of control flow security, we develop the Control Flow Security Model (CFSM) which includes the formal definitions for program semantics and security properties for control flow. CFSM specifies that program execution dynamically follows only certain paths, in accordance with a statically declared security properties specified as Control Flow Constraint Specification (CFCS). We have proposed an efficient control flow security analysis algorithm for verifying that a particular control flow model satisfies the associated security properties. Our work contributes to bridging the gap between abstract specifications of control flow security properties and actual control flow security analysis for binary executables. The effectiveness and the practical usefulness of the approach are exemplified by an illustrative analysis of heap overflow vulnerability.

Millionaire's problem is the base of secure multi-party computation, and its solutions have become basic blocks of many secure multi-party computation solutions. Unfortunately, most solutions to millionaire's problem are based on public key cryptography, and thus are inefficient. Furthermore, all solutions are designed to solve millionaire's problem for natural number case to privately determine which natural number is larger. If the numbers are real, these solutions do not directly work. In this paper, we first propose a symmetric key cryptographic solution to millionaire's problem for natural numbers case, and then generalize it to the case of real numbers, that is to privately determine which real number is larger. We further prove, by simulation paradigm, that these solutions are private. These solutions are really efficient.

In this paper, we propose a quantization-based semi-fragile watermarking algorithm for content authentication. The watermark can be blindly extracted. The formulation of judge threshold is given from the point of probability theory. The tempered areas of watermarked image can be distinguished by the predefined threshold. Our scheme is robust to incidental manipulations while fragile to malicious distortions, and can distinguish the distortions caused by great incidental processing with the malicious tempering. The advantage of our scheme is compared with other algorithms in the last.

Introducing micro-payment mechanism into P2P systems will bring economic incentives to various P2P applications and encourage peers to share their resources. In this paper, we present a new micro-payment protocol, CPay, which exploits unique characteristics of P2P systems. The protocol establishes dynamic consistent hashing map between the set of all peers in the system and its subset of high performance peers. In each transaction, the payer's corresponding high performance peer checks the transaction to make sure that any illegal use of the e-coin would be timely detected. The protocol effectively exploits the heterogeneity of the P2P system and can achieve load balance