Research On The Key Technologies Of Trustworthiness And Trust Model Of Internet-based User Behavior

Internet information system is the main source of human information. With rapid development of e-commerce, e-government and electronic technology, transaction modes of human society are completely changed. Internet applications become more simple and efficient because of new distributed computing technologies. With popularization of Internet, network security problems become more and more complex and traditional trust relationships in human society are facing serious challenges. Because network security incidents occur frequently, communications among network users become more and more careful. Increasing of trust risk will bring negative influences on development of internet. Therefore it is necessary to establish the trusted computing environment so as to ensure continued healthy development of Internet.The main work and contributions of this dissertation are shown as follows:(1) A general objective weighting method is proposed by using internet features, namely Behavior Statistics based Weighting Method(BSWIM). The method is based on the behavior information of user evaluation which is significantly differed from the traditional methods basing on the value information, and it can be used in In STEP. The use of ELECTRE TRI method for evaluating software trustworthiness is also presented and software under evaluation using the method is compared with some predefined norms and is assigned to one of trust level.(2) A model of virtual organization is proposed. Its core is reputation mechanism and it can be extended. When it evaluates trust relationship between nodes, it looks global experience of valuer as main reference. There are constraint significantly for malicious behavior of bad node. This model combines with the heuristic algorithms, it looks the past trust evaluation as important reference. Thus accuracy of evaluation of trust relationship is improved and sensitive degree of algorithm based on node behavior is enhanced. This model looks hope of virtual organization sponsor as important indicator when it evaluates trust relationship between entities. It makes the construction of virtual organization stronger adaptability.(3) A new user feedback mechanism is proposed. This mechanism can combine Qo S index of node and subjective evaluation of valuer and get user feedback information, which can not only reflect trust relationships between nodes effectively, but also eliminate adverse effects on users and whole network caused by frequent feedback. In addition, the concept of evaluator reputation is added, it eliminates false recommenders and false recommendations, enhances reliability and stability of whole system.(4) Trust expression based on multi-dimensional trust vector is proposed. Aiming at problem of traditional computing style based on single trust value is limited in applications of distributed system, can not accurately express multi-dimensional meaning of trust and show the rators’ reliability status, and not support trust decision, this dissertation presents trust expression based on multi-dimensional trust vector. The method of replacing traditional single-value trust with multi-dimensional vector trust can accurately get corresponding trust value on each dimension of trust vector. Introduction of multi-dimensional trust can provide more accurate, personalized service and personalized decision for nodes.(5) Personal decision mechanism based on trust vector is proposed. Aiming at the problem of traditional trust decision mechanism based on single-value trust normally using simple threshold-based judgement cannot meet complex requirement in distributed system, this dissertation presents personal decision mechanism based on trust vector. With supporting of multi-dimension trust model, this mechanism gets detailed classification of reliability vector, combines with the factors of application-related and personal trend, and computes reliability value with richly personal information, so as to get more effective trust decision.