Research On Privacy Protection Based On Blockchain Transaction Scheme

Blockchain technology is developing and applied at a rapid pace.At the same time,more and more leaks of blockchain security and privacy are happening in the society.Due to the existence of the blockchain consensus mechanism,different nodes will calculate and verify the transaction information on the blockchain,so the transaction record data on the blockchain must be made public.Although this method increases the transparency and credibility of the data to some extent,it also brings the risk of user privacy leakage from another perspective.Among them,the privacy protection of the transaction parties' identities and transaction amounts should be paid more attention to.In order to make the blockchain have a broader application prospect,this thesis uses the aggregation signature and ring signature technology to study the privacy protection mechanism of the blockchain transaction system,and proposes solutions to the corresponding problems.The work of this thesis has the following two aspects:(1)Aiming at the traditional Crypto Note transaction model,this thesis improves the transaction input and output transfer mode by adding random numbers,which effectively solves the privacy problem of malicious attackers by adopting some attack algorithms to control part of the input and output for verification and launching the encrypted transaction amount.Aiming at the existing basic transaction scheme of the blockchain,the combined signature algorithm is used to aggregate and sign the transaction amount in multi-input and output transactions,which improves the privacy security and performance of the transaction amount of the basic transaction scheme.Finally,comprehensively improving the traditional transaction scheme and the improved basic blockchain transaction scheme,an improved blockchain transaction scheme based on aggregate signatures is proposed,which not only solves the malicious attack problem in the traditional transaction scheme,but also further strengthens the transaction amount and improves the performance of the solution to a certain extent,so it can be better applied in the field of blockchain transaction solutions.(2)Aiming at the problem that transaction amount and the identity of the two parties can be analyzed and predicted to reveal the privacy of the user from the open and transparent transaction information in the traditional Bitcoin trading system,a fully anonymous blockchain trading system is constructed by combining the aggregate signature and the ring signature in this thesis.The scheme combines the advantages of aggregate signature and ring signature,uses aggregate signature to protect the transaction amount privacy,uses ring signature to protect the address privacy of both parties,and at the same time compresses the transaction information size while protecting the privacy,saving a certain space overhead.Through comparing with the evaluation and analysis of various blockchain privacy protection schemes,it is concluded that the scheme takes both security and performance into account,that is,the privacy protection of transaction information is greatly improved when the reasonable overhead is increased.