Research On Authentication And Data Security Protocol Based On Blockchain

With the development of the Internet of Things,mobile Internet,cloud computing and other information technologies,various applications have generated huge amounts of data.The use of data brings a lot of convenience to human beings,but there are also some problems that need to be solved,such as poor data reliability,data privacy leakage and difficult data sharing and exchange.Blockchain,as an emerging information technology,has the characteristics of decentralization,anti-tamper and publicly validation.It builds a decentralized infrastructure by combining cryptography,consensus mechanism,peer-to-peer network and other technologies,and provides a solution for ensuring data availability and reliability.With the help of the advantages of blockchain technology,this dissertation research contents includes:how to realize the digital identity authentication while protecting digital identity privacy,how to balance the utility and the privacy of data,how to realize effective data sharing and fair exchange of data.The main contributions are summarized as follows:1.For the issues of privacy of digital identity,we propose blockchain-based selective revocation anonymous authentication protocol,which realizes the compatibility of authentication and privacy of digital identity while supporting selective revocation of user credential for the behavior of abusing anonymity.We formalize the system model of blockchain-based selective revocation anonymous authentication protocol.We issue user credentials by virtue of Ethereum smart contract,build user's showing proof by using the re-randomization feature of PS signature,and realize the selective revocation of user credentials by adopting cryptographic accumulator.For the applications of digital identity with multiple attributes,we propose blockchain-based selective revocation multi-attributes anonymous authentication protocol,and analyze the efficiency of the two protocols through simulation experiments.Finally,we demonstrate the practicality of the protocol by deploying a prototype system based on Ethereum smart contracts.2.In order to balance data utility and data privacy,we propose blockchain-based auditable privacy-preserving data classification protocol,which can audit the correctness of data classification of data processing center and guarantees the utility and the privacy of data.We formalize the model of blockchain-based auditable privacy-preserving data classification protocol.We design new group signatures to authenticate the data and use the public audition feature of blockchain to audit the result of data classification.We further propose blockchain-based auditable privacy-preserving data classification against malicious verifier protocol to improve the data utility.We design new controllable linkable group signatures to authenticate the data and use blockchain smart contracts to maintain the correctness and transparency of data classification which supports flexible and privacy friendly access to the data.The performance analysis show that the proposed protocols are superior to existing technologies in terms of functionality and computational overheads,the validity of the protocol is verified by the combination of Ethereum smart contract.3.For guaranteeing effective data sharing and the fairness of data exchange,we propose blockchain-based data sharing and fair exchange protocol,which guarantees the reliability and integrity of data and supports fair data exchange.For the software updating application,we formalize the model of blockchain-based data sharing and fair exchange protocol.We construct a conditional payment smart contract and establish an incentive mechanism for transmission nodes.We integrate outsourcing attributed-based signatures with double authentication preventing signatures to generate the proof-of-delivery for a transmission node to realize the effective data sharing and fair data exchange.Finally,we verify the validity of the protocol by deploying the protocol on Ethereum smart contracts.