Research On Ring Signature Scheme In Blockchain Environment

Each user in the blockchain has a virtual identity,and the user uses the virtual identity to transact without revealing its real identity in reality,that is,to achieve the anonymity of the blockchain.However,in the blockchain digital currency transaction,because all transaction information is transparent and open,the attacking opponent can use transaction graph analysis and other means to analyze the multiple transaction information of virtual identity,and according to the correlation between transactions,the real identity of this virtual identity,in reality,can be inferred.Therefore,blockchain does not have a true sense of anonymity and still has a high risk of privacy leakage.As a decentralized group signature scheme,a ring signature can hide its identity in a group of ring members,has the characteristics of anonymity,does not require other members to participate in collaboration with trusted third parties,and can be used to protect the identity privacy of the transaction initiator in the blockchain.Therefore,this paper takes ring signature as the main research object,studies the characteristics of the ring signature scheme suitable for blockchain,and analyzes the shortcomings of the existing ring signature scheme;the deficiency of the anonymity of the existing scheme is limited by the length of the signature,a new ring signature scheme is proposed,and a transaction protocol suitable for the blockchain is constructed based on the scheme.The main research work of this paper is as follows:(1)Research and analysis of existing blockchain uplink signature schemes.Through the survey,it is found that there are certain deficiencies in the privacy protection scheme using ring signatures on the blockchain,and the length of the signature is positively correlated with the number of ring members.To control transaction costs,existing schemes often need to limit the length of signatures,thereby limiting the number of ring members and failing to achieve high anonymity.And through the analysis of Crypto Note and other ring signature schemes,it is summarized that the ring signature scheme suitable for blockchain should have the characteristics of short signature length,high computational efficiency,easy expansion to multiple layers,and easy to add linkability.(2)Aiming at the problem that anonymity is limited by signature length,a new constantlevel ring signature CRS scheme is proposed.The scheme is based on a strong RSA accumulator,which realizes the separation of the signature length from the number of ring members through the accumulation of the public keys of the ring members,that is,the signature length is always a constant length regardless of the number of ring members.The scheme proved to be anonymous and unforgettable under the random oracle model.Comparing the algorithm complexity analysis and experimental simulation with the existing scheme,the CRS scheme in this paper can have higher advantages under the trade-off between signature length and computational efficiency,and the advantages are more obvious when achieving higher anonymity.(3)The CRS scheme in this paper is extended,and a new Ring CT protocol for ringsecret transactions is designed in combination with confidential transactions.By adding linkability to the CRS scheme in this article and extending it to multiple layers,the protocol uses Pedersen’s commitment to hiding the transaction amount,realizing privacy protection for the identity of the transaction sender and the transaction amount in the blockchain digital currency transaction.The Agreement has been shown to be anonymous,non-defamatory,and balanced.Finally,experimental simulation is compared with the existing scheme,and the results show that the Ring CT protocol in this paper has advantages in signature length and computational efficiency when achieving higher anonymity.