Blockchain-Supported Fuzzy Keyword Search Using Homomorphic Asymmetric ElGamal Encryption in Cloud Environments

Blockchain technology ensures immutable records for search-related data, fostering trust and verifiability in search history and metadata.Integrating blockchain with fuzzy search enhances decentralized data management by enabling secure information retrieval, even with partial or imperfect matches.The proposed architecture empowers a cloud server to manage encrypted data while efficiently responding to user queries.Data owners encrypt documents using Homomorphic Asymmetric Searchable Encryption (HASE) with the ElGamal algorithm, storing them in the cloud alongside an encrypted keyword index maintained on the blockchain.Upon receiving user requests, blockchain nodes decrypt the index and forward the query to the cloud, which generates a fuzzy duo trapdoor for retrieval.The system delivers exceptional performance across key metrics, including execution time, space efficiency, and peak signal-to-noise ratio (PSNR).This architecture effectively balances data security, confidentiality, and verification, addressing critical challenges in cloud environments.