Anonymous Technology Based On Blockchain

As a new technology,block chains have attracted wide attention.The most prominent application of block chains is in the field of digital money.For example,Bitcoin is the most famous product based on block chain technology.We can consider that Block chain is formed by different blocks which are linked through their Hash value,and each block contains a certain amount of transaction information.Unlike traditional transactions,transactions on block chains are interlinked.Specifically,as participants in block chains,each user maintains an address evolved from their public key and a private key.The recipient of each new transaction is the unique address of the participant,and the initiator uses its private key to sign a transaction in the block chain as input to the new transaction.Such structure of block:chains is to achieve the goal of decentralization under the premise of protecting users' privacy.However,it is precisely because of this interconnected structure between transactions that lead many scholars question their anonymity,people can calculate the current digital currency balance of any address easily,at the same time,there are also many works to analyze the relationship between transaction addresses and people in the real world.Therefore,improving the anonymity of block chain system has become an important research direction in the field of digital currency.The main work of this paper is to hide the transaction amount and break the direct link between transactions to improve the anonymity of block chains on the premise of ensuring auditability.This work can be divided into the following parts:(1)In terms of hidden transaction amount,this work refers to the assumption put forward by Maxwell et al,the difference is that this paper uses Pedersen commitment instead.This work construct the public and private keys in the commitment phase and audit the transaction amount in the signature verification phase.(2)This paper absorbs the idea of one-time address in CryptoNote protocol and simplifies it to protect the identity information of the transaction recipient,(3)For the initiator of the transaction,this paper uses the linkable ring signature to break the relationship between transactions,at the same time,the "multiple payments"behavior of malicious users is also prevented in the process of verifying ring signature through the construction of this work.At last,this paper describes the specific flow of the protocol in detail and gives the structure of the transaction and operation mechanism in the modified block chain.By combining the above schemes,this paper finally achieves high-level anonymity of transaction amount and identity information of both parties in the block chain.