16744851
Using Trust for Secure Collaboration in Uncertain Environments
The SECURE project investigates the design of security mechanisms for pervasive computing based on trust. It addresses how entities in unfamiliar pervasive computing environments can overcome initial suspicion to provide secure collaboration.
28565174
Trust Evolution Policies for Security in Collaborative Ad Hoc Applications
The vision of pervasive computing has introduced the notion of a vast, networked infrastructure of heterogeneous entities interact through collaborative applications, e.g., playing a multi-player online game on the way to work. This will require interactions between users who may be marginally known or completely unknown to each other, or in situations where complete information is unavailable. This introduces the problem of assigning access rights to such marginally known or unknown entities. Explicit trust management has emerged as a solution to the problem of dealing with partial information about other users and the context in which the interaction takes place. We have implemented an access control mechanism based on the human notion of trust, where recommendations or initial participation in low risk interactions will allow entities to slowly build trust in each other. As the trust between two entities grows, interactions that entail a higher degree of risk may be allowed to proceed. We have used this mechanism in a simple role-based access control mechanism that uses trust to assign roles to users in a distributed blackjack card game application. This application allows us to experiment with different policies for trust-based admission control and trust evolution. In this paper we present an evaluation of policies specifying trust dynamics, which shows that our prototype reacts appropriately to the behaviour of other users and that the system updates trust values and implements admission policies in a manner similar to what would be expected from human trust assessment. This indicates that trust evolution policies can replace explicit human intervention in application scenarios that are similar to the evaluated prototype.
16254824
Trust Propagation in Small Worlds
The possibility of a massive, networked infrastructure of diverse entities partaking in collaborative applications with each other increases more and more with the proliferation of mobile devices and the development of ad hoc networking technologies. In this context, traditional security measures do not scale well. We aim to develop trust-based security mechanisms using small world concepts to optimise formation and propagation of trust amongst entities in these vast networks. In this regard, we surmise that in a very large mobile ad hoc network, trust, risk, and recommendations can be propagated through relatively short paths connecting entities. Our work describes the design of trust-formation and risk-assessment systems, as well as that of an entity recognition scheme, within the context of the small world network topology.
14204568
End-to-End Trust Starts with Recognition
Pervasive computing requires some level of trust to be established between entities. In this paper we argue for an entity recognition based approach to building this trust which differs from starting from more traditional authentication methods. We also argue for the concept of a ”pluggable” recognition module which allows different recognition schemes to be used in different circumstances. Finally, we propose that the trust in the underlying infrastructure has to be taken into account when considering end-to-end trust.
21338568
Research on Risk Probability Estimating Using Fuzzy Clustering for Dynamic Security Assessment
Effective network security management requires assessment of inherently uncertain events and circumstances dynamically. This paper addresses the problems of risk probability assessment and presents an alternative approach for estimating probability of security risk associated with some interaction in ubiquitous computing. A risk probability assessment formula is proposed, and an estimating model adopting the Fuzzy C-Means clustering algorithm is presented. An experiment based on DARPA intrusion detection evaluation data is given to support the suggested approach and demonstrate the feasibility and suitability for use. The practices indicate that fuzzy clustering technique provides concepts and theoretical results that are valuable in formulating and solving problems in dynamic security assessment.
2275333
Risk probability estimating based on clustering
Ubiquitous computing environments are highly dynamic, with new unforeseen circumstances and constantly changing environments, which introduces new risks that cannot be assessed through traditional means of risk analysis. Mobile entities in a ubiquitous computing environment require the ability to perform an autonomous assessment of the risk incurred by a specific interaction with another entity in a given context. This assessment will allow a mobile entity to decide whether sufficient evidence exists to mitigate the risk and allow the interaction to proceed. Such evidence might include records of prior experiences, recommendations from a trusted entity or the reputation of the other entity. We propose a dynamic mechanism for estimating the risk probability of a certain interaction in a given environment using hybrid neural networks. We argue that traditional risk assessment models from the insurance industry do not directly apply to ubiquitous computing environments. Instead, we propose a dynamic mechanism for risk assessment, which is based on pattern matching, classification and prediction procedures. This mechanism uses an estimator of risk probability, which is based on the automatic clustering of defining features of the environment and the other entity, which helps avoid subjective judgments as much as possible.
12301426
A Novel Symmetric Cryptography Based on Chaotic Signal Generator and a Clipped Neural Network
Recently, a novel encryption algorithm that integrates Haar wavelets transformation into chaotic signal generator, was proposed by R.Luo et al. In this paper, we first analyzed the merits and demerits of this algorithm. Then an improved scheme which uses a clipped neural network is proposed. Both theoretical analysis and computer simulations show our proposed scheme succeeds in overcoming the defects of Luo’s algorithm while retaining all its merits. Moreover, the way that the clipped neural network evolves may present a new idea to the cryptography.
134347
VR-GIS: an integrated platform of VR navigation and GIS analysis for city/region simulation
This paper introduces a virtual city oriented VR-GIS platform which synthesizes several latest information technologies including virtual reality, 3D geographical information system, remote sensing and multi-dimensional visualization. The platform is a seamless integration of VR functions and GIS analysis methods, which can be used to organize and present massive spatial data. It also supplies 3D spatial analysis functions, 3D visualization for spatial process and natural simulation, and serves as an engine platform for digital city.
38601346
A model and algorithm of two-dimensional optimum layout in blanking
In this paper, a model and algorithm of optimum layout is proposed for blank layout of single pattern on single rectangular sheet. The approach arranges the cutting patterns on rectangular sheet in the typical style of Double Opposite Layout (DOL). The remains of the sheet, which has been left in one direction after arranging patterns, called as "Step Leavings" (SL) is considered while the optimum layout is discussed We make full use of material of the sheet, including the A in x-direction and y-direction, and set up a reasonable mathematical model for the two-dimensional optimum layout. A corresponding algorithm is also provided to work out the optimum layout quickly and automatically. In this way, we can get the best layout scheme to arrange the maximum shapes on the sheet.
14028105
Scalability of heterogeneous computing
Scalability is a key factor of the design of distributed systems and parallel algorithms and machines. However, conventional scalabilities are designed for homogeneous parallel processing. There is no suitable and commonly accepted definition of scalability metric for heterogeneous systems. Isospeed scalability is a well-defined metric for homogeneous computing. This study extends the isospeed scalability metric to general heterogeneous computing systems. The proposed isospeed-efficiency metric is suitable for both homogeneous and heterogeneous computing. Through theoretical analysis, we derive methodologies of scalability measurement and prediction for heterogeneous systems. Experimental results verify the analytical results and confirm that the proposed isospeed-efficiency scalability works well in both homogeneous and heterogeneous environments.
14185433
Affective Computing Model Based on Rough Fuzzy Sets
In human affective research, the fuzziness and roughness of the affective computing is the chief difficult. This paper builds a novel affective model based on rough fuzzy sets for the first time and presents a serial of static description results, which effectively solve the fuzzy and rough problems in affective computing. The model can realize the precision control of affective computing conveniently. Finally, the simulation shows that the results of the model for the affective static description are reasonable. This paper extends the results in (Yong Chen and Tong He, 2005) and lays the foundation of the affective computing in depth