Research On Secure Data Transmission In Internet Of Things

The Internet of Things(IoT)connects a large number of devices through an ubiquitous wireless network.By connecting objects and people,IoT trans-forms the physical world into a digital system.Although IoT grabs the global attentions,it also faces global security threats.To further promote the devel-opment of IoT technology,the IoT security is undoubtedly an important and fundamental guarantee.In order to protect the privacy and security of IoT data,it is necessary to conceal the data contents and characteristics of data flow,ensure the availability of the network,and prevent malicious attackers from breaking the network availability.To protect the IoT data confidentiality,in-tegrity,non-repudiation and availability,this thesis studies the location privacy protection issues and secure data transmission issues in IoT.Markov models are built in this thesis to analyze the network performance of secure data trans-mission mechanisms,providing quantifiable criteria for selecting appropriate secure transmission protocols in different network environments.The main contributions of this thesis are as follows,(1)The previous source location privacy protection solutions conceal the contents of data packets.It is difficult for intermediate nodes to verify the in-tegrity of data packets.Active attackers can inject false or polluted messages to disrupt the network.This thesis uses key predistribution mechanism to im-prove the transmission efficiency of the source location privacy protocol.It ensures that intermediate nodes can filter out polluted and dummy messages by probabilistic authentication.Only real messages are forwarded in the network to improve the network availability.(2)This thesis proposes a probabilistic secure data transmission protocol to transmit encrypted messages in an adaptive manner.It avoids the communica-tion overhead caused by handshaking in the previous data encryption protocol.The receivers with the matched key immediately decrypt the data,which im-proves the transmission efficiency.In addition,a three-dimensional Markov model is constructed to analyze the impact of wireless communication colli-sions and key predistribution mechanisms on the performance of the secure encrypted data transmission.The analysis and simulation results prove the ac-curacy of the 3-D markov model.(3)This thesis also combines collision backoff and key selection to de-sign an authentication protocol in opportunistic routing based IoT networks.In order to improve the authentication efficiency,the authentication protocol gen-erates authentication information based on the combination of the new message and previous non-conflict but unauthenticated messages while attempting dif-ferent keys.Once the key matches,the unauthenticated messages and the new message can be verified altogether.In this way,the authentication over-head can be reduced to be independent with the number of keys attempted.At the same time,the interaction process between non-coordinated transmissions and key selections in the authentication protocol is modeled as a three-dimensional(3D)Markov model.Unverified packets in the previous states will be passed to subsequent states.The three-dimensional Markov model also captures the dynamic topology of the mobile IoT.(4)This thesis also proposes a four-dimensional(4D)Markov model to analyze the impact of dynamic topology on data authentication protocols.The model also captures the co-authentication process in a limited link duration with a matched key found.The first three dimensions capture an authentication cy-cle and the fourth dimension captures the unauthenticated messages among cy-cles.The thesis proposes three cross-layer data authentication protocols with opportunistic authentication and channel access coupled to different extent.Ac-cording to the simulation results,the four-dimensional model is general and ac-curate.Also,opportunistic data authentication protocols perform better than previous authentication protocols.The design of closely coupled opportunistic authentication and channel access protocol is the key to unlocking the potential of opportunistic authentication protocols.