Research And Application On Blockchain Based Key Technology In IoT Information Security

Data is the internal driving power of the Internet of Things(IoT),which outline the social activities of individuals in the real world,and also intuitively reflect a person’s health status,behavior,trajectory and other private information.It is worthy of attention that above characteristics make the IoT expose many problems:(1)The security goals of the IoT include confidentiality,integrity,undeniability,privacy,limited disclosure and so on,which are difficult or costly to achieve;(2)loT devices and service providers generally have the tendency of "focusing on functions and ignoring security".With the continuous updating of attack means and technology,the threshold and difficulty of attack are continuously reduced.(3)Most loT architectures are based on the centralized design of "end-to-cloud",which has problems such as single point of failure and high maintenance cost.Moreover,the cloud platform is semi-trusted or even malicious.Its unauthorized operations like analysis,peeping,and tampering will seriously violate the privacy of the data owner.Blockchain is an emerging data management technology with the advantages of decentralization,tamper-proof,traceability and anonymity,which can be applied to the data management of the IoT.Therefore,aiming at the requirements of efficient sharing and privacy protection of big data in IoT environment,this dissertation combines blockchain technology with access control and modern cryptography to study the key technologies of IoT information security,and propose corresponding application schemes.The main works of this dissertation include:(1)In order to meet the requirements of distributed and dynamic access control in the IoT environment,this paper designs and implements an IoT access control system(Fabric-IoT)based on blockchain and ABAC.First,the basic resource and policy model are defined.On this basis,an access control system based on blockchain and ABAC for IoT is designed and implemented.In this system,there are 3 smart contracts to provide distributed,fine-grained and dynamic access control.The experimental results show that Fabric-IoT can maintain high throughput in large-scale user request environment,reaching consensus efficiently in distributed system to ensure the consistency of data.(2)To meet the requirements of distributed data encryption storage and efficient distribution of the IoT in the big data environment,this paper proposes a ciphertext policy attribute-based encryption(CP-ABE)scheme of the IoT information centric network(IC-IoT)with zero-knowledge proof(ZKP).The non-interactive zeroknowledge proof protocol is introduced into CP-ABE key existence proof to reduce the bandwidth consumption caused by invalid ciphertext transmission.Based on the information-centric network framework(ICN),a new asynchronous distributed content distribution network system for IoT(DPS-IoT)is proposed,and tamper-proof storage of ZKP evidence and policies is implemented on the Fabric-IoT based platform.Experimental results show that compared with the existing research,the proposed system has great advantages in transmission bandwidth utilization and system throughput.(3)Aiming at the requirements of efficient identification and authentication in the IoT under the condition of multiple participants,this paper proposes an identity based multi signature scheme based on Schnorr protocol.In the scheme,the Merkel tree of public key verification supporting m-n threshold is introduced,which can support the multi signature of the IoT cluster when there are offline or faulty devices.In addition,the alliance blockchain is used to replace PKG as the service provider of decentralized secret key generation,distribution and verification,so as to ensure that the data is not tampered with and prevent the dishonesty or malicious behavior of PKG.Finally,in the framework of general forking lemma,a detailed security proof is given,and the feasibility and performance of the proposed scheme are further verified by theoretical analysis and simulation experiments.(4)According to the requirements of trust management of vehicular ad-hoc networks(VANETs),this paper proposes a trust management system of VANETs based on blockchain.Firstly,by analyzing the attack model and trust model of VANETs,a vehicle trust evaluation algorithm based on hidden Markov model is proposed.On this basis,a trust management system based on Hyperledger alliance chain is implemented,which can ensure that the sensitive data in VANETs system is not tampered and the historical behavior can be traced.