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Browsing by Author "Chakraborty, Sudip, author"

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    A vector model of trust to reason about trustworthiness of entities for developing secure systems
    (Colorado State University. Libraries, 2008) Chakraborty, Sudip, author; Ray, Indrajit, advisor; Ray, Indrakshi, advisor
    Security services rely to a great extent on some notion of trust. In all security mechanisms there is an implicit notion of trustworthiness of the involved entities. Security technologies like cryptographic algorithms, digital signature, access control mechanisms provide confidentiality, integrity, authentication, and authorization thereby allow some level of 'trust' on other entities. However, these techniques provide only a restrictive (binary) notion of trust and do not suffice to express more general concept of 'trustworthiness'. For example, a digitally signed certificate does not tell whether there is any collusion between the issuer and the bearer. In fact, without a proper model and mechanism to evaluate and manage trust, it is hard to enforce trust-based security decisions. Therefore there is a need for more generic model of trust. However, even today, there is no accepted formalism for specifying and reasoning with trust. Secure systems are built under the premise that concepts like "trustworthiness" or "trusted" are well understood, without agreeing to what "trust" means, what constitutes trust, how to measure it, how to compare or compose two trusts, and how a computed trust can help to make a security decision.
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    Trust based routing protocol in MANET
    (Colorado State University. Libraries, 2006) Poolsappasit, Nayot, author; Chakraborty, Sudip, author; Indrajit, Ray, author
    Traditional network routing protocols find the shortest path by minimizing a cost over the paths. Number of hops is the most common metric to measure this cost of forwarding. However, this administrative cost metric is not guaranteed to have the same level of quality in mobile ad hoc networks (MANET). In addition malicious nature of nodes augments the problem even further. There is a need for generic cost metric to find the most reliable path for forwarding the packets. We propose a trust-based metric for routing in MANETs. This metric works as a reliability measure of nodes and the ad hoc routing protocol tries to find the most reliable path. We propose a quantitative measure of trustworthiness of a node based on node's properties like signal strength, stability, node's performance to forward packets and its rating by other nodes. To our knowledge, our approach is the first attempt to use a generic trust metric for reliable routing in MANETs.