Research On Key Security Technologies Of Sensing Environment In Internet Of Things

With maturation of the RFID technology and fast growth of smart terminals,Internet of Things is gaining more and more attention and is probably becominganother industrial revolution after the Internet. However, applications using RFIDdevices or smart terminals face more and severer security issues compared to thetraditional Internet applications: entity trust, privacy protection, securing routingand intrusion detection, for instance, which are the key problems when building asecure and trustworthy IoT environment. Analyses and researches of these keyissues is of important significance for reinforcing the infrastructures and the wholeIoT system. Based on the existing works and ideas, this dissertation conducts furtherresearches aiming to find effective and efficient solutions to the critical issues.First of all, there are distributed and decentralized services in the IoTenvironments, trust of entities(human-human, object-object and object-infrastructure)is conditional and environment-dependent. We build a general hierarchical IoT trustmodel for theoretical and practical support. Event deduction is employed in theaccess and sensing layers, the improved D-S deduction detects abnormal routingevents efficiently while a VICD schema is designed to detect terminal node trust andovercomes the RFID short range limitation. In the organization layer, a centralizedschema is employed to maintain organization reputation. The organizationreputation is calculated by node trust feedback, the layered design seperates trustheterogeneity of different entities, meanwhile the trust flow interacts between layers:node authorization refers to the organization reputation, and the authorization trustand routing trust converges upwards to the organization reputation.Secondly, in the object locating applications, we design a location update andquery architecture supporting precise and fuzzy queries for all kinds of objects, thenwe propose a tree and frame based location privacy protection schema, whichprevents possible multi-precision continuous attacks. An improved trilaterationmethod is used to identify objects’ relative locations on the physical layer, ananonymity-tree is maintained for topology stability and query efciency on thenetwork layer and a frame based group building approach is proposed to maximizeconsistency of existing anonymity groups. The proposed approach generates largercommon subset of built anonymity groups and protects location privacy efficiently.Thirdly, the belonging organizations, service required and trust of sensingnodes are heterogeneous since the IoT environment is complicated. We propose aclique-based routing approach, which guarantees the routing control security,meanwhile improves routing efficiency and reliability. Routing failure caused by incompatible strategy is reduced by constructing clique structure and shortening thelogical path.Finally, we introduce an possible attack scenario in which maliciousorganizations deploy numerous RFID readers in a partial region. We frst combinethe report nodes together and form a two-player dynamic game with a detectingnode in a regular network, then we propose an improved cooperative game in theattacker dominated network where detecting nodes cooperate to evaluate trust of anunknown node by its organization reputation, the node’s prior trust and nodecombination are updated according to a trustworthy reference report, thereforemalicious node weights are reduced meanwhile a new Bayes equilibrium is achieved.The cooperative game improves successful deduction rate and decreases forgedreports signifcantly.