Research On Signature Algorithm And Its Application In Blockchain

As a new technical paradigm,blockchain,which has the features of decentralization,nontampering,traceability and public accessibility,can bring the new development opportunities for all walks of life,and thus starts a research boom in the global.The technology can be widely used in the fields of finance,cross-border payment,digital bills,supply chain and medical care in the future.Cryptocurrency is a kind of digital currency that uses cryptographic technology to ensure the transaction security.As the first decentralized cryptocurrency,bitcoin successfully has applied the blockchain technology to achieve direct interaction of value.However,the openness of blockchain technology has severely threatened the privacy of traders in the bitcoin system,and the transaction verification speed is extremely slow,which is difficult to support the daily transactions in the legal currency.In addition,in the existing sharing economy scenario,the network operation cost is high and the privacy leakage is serious,but blockchain technology can provide a solution for these issues.Therefore,this paper mainly studies and explores from the following two aspects:1.For the privacy and transaction delay problems in the cryptocurrency system,a bitcoin transaction scheme is proposed to support the privacy protection and fast signature verification.In the new scheme,firstly,the user's privacy in the bitcoin transaction is protected based on Paillier encryption algorithm.Secondly,an aggregate interactive signature scheme is constructed by using the interactive incontestable signature and aggregate signature technology,which greatly reduces signature's storage space.Then,a new scheme is proposed to effectively protect the privacy and quickly verify the signature.Finally,the new scheme is proved to be unforgeable under the random oracle model.Performance analysis shows that the proposed scheme can support effective privacy protection and signature verification.2.Aiming at the problem of high network operation cost and privacy leakage in the existing sharing economy scenario,a new sharing economy scheme is proposed to ensure fairness and privacy protection.In the new scheme,firstly,through a third-party to issue anonymous vouchers which users redeem for bitcoin,the unlinkability of transaction is achieved.Secondly,the proposed scheme uses the smart contract and blind signature technology to ensure the fairness and anonymity between the parties involved in the transaction.Finally,double using(the property owner rents his goods to different users)and double spending(the user spends his bitcoin multiple times)can be detected and prevented.Security analysis and efficiency analysis show that the proposed scheme is secure and effective.