Biblio

Computational trust is the digital counterpart of the human notion of trust as applied in social systems. Its main purpose is to improve the reliability of interactions in online communities and of knowledge transfer in information management systems. Trust models are formal frameworks in which the notion of computational trust is described rigorously and where its dynamics are explained precisely. In this paper we will consider and extend a computational trust model, i.e., JØsang's Subjective Logic: we will show how this model is well-suited to describe the dynamics of computational trust, but lacks effective tools to compute initial trust values to feed in the model. To overcome some of the issues with subjective logic, we will introduce a logical language which can be employed to describe and reason about trust. The core ideas behind the logical language will turn out to be useful in computing initial trust values to feed into subjective logic. The aim of the paper is, therefore, that of providing an improvement on subjective logic.

In this paper, we present LAPA, a framework for automatically analyzing network security risk and generating attack graph for potential attack. The key novelty in our work is that we represent the properties of networks and zero day vulnerabilities, and use logical reasoning algorithm to generate potential attack path to determine if the attacker can exploit these vulnerabilities. In order to demonstrate the efficacy, we have implemented the LAPA framework and compared with three previous network vulnerability analysis methods. Our analysis results have a low rate of false negatives and less cost of processing time due to the worst case assumption and logical property specification and reasoning. We have also conducted a detailed study of the efficiency for generation attack graph with different value of attack path number, attack path depth and network size, which affect the processing time mostly. We estimate that LAPA can produce high quality results for a large portion of networks.