Research On Key Technologies Of Blockchain Electronic Transaction Security

Blockchain electronic transaction systems can securely maintain a distributed ledger in an open peer-to-peer network,which has received widespread attention from academia and industry.This paper focuses on the key technologies of blockchain electronic transaction security.Because privacy of users are leaked in Bitcoin,a coinmix scheme based on ring signature was proposed to enhance the anonymity of Bitcoin.Consensus protocols based on Proof-of-Work and Proof-of-Stake are two kinds of consensus protocols used by current blockchain electronic transaction systems.In order to improve the processing speed of the blockchain electronic transaction systems based on Proof-of-Work and reduce the transaction latency,a verification group consensus protocol based on Proof-of-Work is proposed.In order to improve the processing speed of the blockchain electronic transaction systems based on Proof-of-Stake and reduce the transaction latency,a sharding consensus protocol based on Proof-of-Stake is proposed.In order to ensure the security of the communication protocol between a blockchain electronic transaction system and external systems,a formal analysis method based on logical reasoning is proposed to analyze the security of electronic transaction protocol.The main research work and innovations of this paper include:A coinmix scheme based on ring signature is proposed to enhance the anonymity of Bitcoin.The scheme uses a centralized server to confuse transaction records to avoid the disadvantages of deployment and upgrade difficulties in distributed service.This paper designs an elliptic curve ring signature algorithm to be compatible with current Bitcoin system.Users utilize the elliptic curve ring signature algorithm to sign the output addresses so that the centralized server can not recognize the owner of an address.The scheme uses a group transaction of Bitcoin to ensure that the centralized server cannot steal the users' Bitcoin.Users don't have to worry about the centralized server may steal Bitcoin or secretly record transaction information.A verification group consensus protocol based on Proof-of-Work is proposed to improve the processing speed of the blockchain electronic transaction systems.The protocol requires the node to compete to join in the verification group through the Proof-of-Work.It inherits the security of the Proof-of-Work.It improves the speed at which nodes can agree on blockchain data by narrowing the consensus range.The leader node that generates the block is randomly selected replaces the mechanism of competing for block generation.It avoids the situation to generate blockchain branches.After experiments testing,the prototype system can achieve a processing speed of approximately 1,800 transactions per second and an average transaction latency of 3 seconds.This paper proposes a sharding consensus protocol based on Proof-of-Stake to implement the function of parallel processing transactions.It improves the processing speed of the blockchain electronic transaction systems.nodes compete for join in the verification group according to their own stake,which saves the computing resources.The protocol randomly selects members of the verification group from the nodes that own stake to ensure the security of the system.A trusted and validated transaction confirmation strategy enables fast transaction confirmation in the case of small amounts.The inter shards locking mechanism ensures that a transaction can only be processed by one shord at a time,avoiding the possibility of double-spending attacks.After experiment testing,the prototype system can achieve a processing speed of more than 6,000 transactions per second and a fast transaction confirmation latency of less than 2 seconds.The transaction processing speed can be continuously increased with the number of shards.A formal method based on logical reasoning is proposed to analyze the security of electronic transaction protocols.This paper introduces a simple time expression to describe the protocol events time in the existing logical reasoning method.The proposed formal analysis method extends the time characteristics of logical inference rules and can be used to analyze the accountability,fairness and timeliness of electronic transaction security protocols.