Blockchain-based noisy data sharing control protocol

Blockchain provides a trusted channel for information sharing in an untrusted network.However, blockchain ledgers are public and transparent.Hence, the sensitive data stored in plaintext on the blockchain will compromise user privacy.Considering privacy preservation, users are more inclined to provide noisy data.And in different application scenarios, the level of data noise that users need to provide also varies.To this end, a secure, efficient, and searchable noisy data sharing control protocol was proposed based on the blockchain and smart contract technology with the ciphertext policy attribute-based encryption (CP-ABE) algorithm.First, an outsourced CP-ABE algorithm was introduced to reduce the computing burden on the user side.Secondly, smart contract was implemented to perform data search on ciphertext, which could prevent malicious operations by malicious servers.Third, the proposed protocol reduced the data update complexity to O(1), which is friendly to the scenarios with real-time data update.Final