Certificateless searchable attribute-based encryption approach for cloud data based on blockchain

Searchable encryption is a method which permits cloud servers to recover consumers' requested data even when the contents are encrypted. However, many current searchable encryption algorithms only offer single keyword recovery and are subject to keyword guessing attacks. This work presents a blockchain-based multi-keyword searchable encryption technique based on a certificateless approach. Further, we employ attribute-based encryption to protect sensitive information and a certificateless cryptosystem to encode keywords. The encrypted files are uploaded to the cloud, whereas the encoded keyword indexes are kept on the blockchain, assuring the encrypted indexes' tamper resistance. Our approach also supports multi-keyword search over encrypted data. We created a fair payment smart contract to support the exchange of service costs with the owner of the information and the cloud service provider in the event of successful search results. The study reveals that our technique outperforms other related techniques in terms of computing efficiency.