On-chain anonymized traceability scheme based on outsourced data

In the traditional blockchain-based outsourcing data storage and verification, there is little research on the protection of user identity privacy, because the querying user often needs to verify the querying outsourcing data, and the cloud server also hopes to be able to pursue the malicious behavior users. In the open network environment, all monoliths are convergent. Statute to the security of the smart contract, due to the blockchain's non-tamperable nature, once the smart contract is triggered, it is not under the control of any single private node, thus the blockchain as a third party in the data outsourcing scenario ensures that user access to the validation and accountability history is not tampered with, and ensures that the validation results are fair. In this paper, we perform anonymous and accountable user authentication for data query under the premise of securely storing outsourced data, which protects the privacy of users and prevents their malicious behaviors.