Computer Science

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Browsing Computer Science by Subject "Computer security"

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    Modelling trust management in agent-to-agent security scenario
    (2006) Nkosi, Mzomuhle Thuthuka; Adigun, M.O.
    Over the previous years, researchers have given much attention to explore the effective use of distributed systems to search, retrieve, and share information. Mobile agent technology has had a great impact in providing solutions in different dimensions of distributed systems. This research work presents the development and implementation of trust management model that ensures agents communicating in a Context-Aware Component Interfacing Partem (CACIP) based Service Oriented Distributed Environment. The Agent-to-Agent Trust Management model is proposed to ensure security of agents that want to access services from the CACIP. The developed model uses a reputation-based approach to evaluate tmstworthiness of each agent. Each agent must be authenticated and authorized in order to get an access to services in CACIP. The trust management model ensures trustworthiness of each agent participating in a CACIP based environment. Mobile agent security requirements were considered in developing the model. The developed model was implemented to demonstrate how requesting agents are authenticated and authorized before accessing services. Simulation of the model was also conducted to assess the performance to the model. The results show the efficiency of the model when agents simultaneously make requests over a given amount of time. The performance of the model shows scalability when number of requests increases. The use of both foreign and local reputation to evaluate trust of agents guarantees that all agents that access services, are trustworthy.
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    Provisioning of secure Multi-Agent Systems (MAS) based on trust contracts
    (2004) Biyela, Philile Diligent; Adigun, M.O.
    This research work focuses on the development of an Interaction Security Contract (ISC) mechanism that enhances the capability of agents to protect themselves against compromised entities in Multi-Agent system. To realize the framework, two tasks were carried out namely ® a simulation of an agent based system was created and trust accuracy levels based on the proposed mechanism were evaluated to establish the significance of the proposed security scheme; and (if) a security-aware agent-oriented shopping mall system was designed and implemented to demonstrate the proposed contract based security model. The results obtained are threefold; (i) This study was able to establish that trust models based on reputation do not obtain accurate trust values for agents to make correct trust decisions in agent systems; (ii) it was established that it was even riskier to form collaborations without any trust model in place as agents collaborated with agents whose security status was not known to them. This clearly shows that agents were at risk of being compromised; and (iii) it was established that if agents publicize their security properties truthfully, trust in the overall agent systems will be gready improved as agents themselves will only be collaborating with agents who meet their specified level of trust In conclusion the study advocates the employment of the proposed Interaction Security Contract (ISC) mechanism, since it was demonstrated how knowledgeable trust relationships can be formed and improved in agent based systems.