Anonymous Hidden Transaction Model for Blockchain Systems

Blockchain system is the novel decentralized trustworthy network and it is widely used for the digital asset management. In the bitcoin-like blockchain systems, the transactions are finished via the cryptography scripts. The user's public key hash code and address information are recorded in a locking script, and posted on the blockchain for verification. By analyzing all transaction records of an address, we can obtain the transaction behaviors of the address, including transaction frequency, number of transactions, and typical address for long-term usage. Sometimes, user privacy will be impacted according to the above analysis. To solve the problem, this paper proposes an anonymous hidden transaction model of the blockchain systems through modifying the original blockchain transaction script. In the proposed multi-layer model, the blockchain transaction system is divided into three layers. For top to bottom, they are shell account (under the public address) layer, hidden account (under the private address) layer and the user layer respectively. The hidden accounts can map to different shell account to complete the transactions. We combine the zero-knowledge proof mechanism so that the finished transaction can be verified by any user. The theoretical analysis shows that our proposed method can effectively protect transaction user information and realize truly anonymous transactions.