Enhancing IoT Security and Efficiency: A Blockchain-Assisted Multi-Keyword Searchable Encryption Scheme

The Internet of Things (IoT) has expanded rapidly, generating vast amounts of data that require effective protection. Traditionally, the attribute-based searchable encryption (ABSE) as been used within IoT to maintain data privacy and integrity. However, existing ABSE approaches often rely on centralized systems that are susceptible to single-point failures and are inefficient in terms of decryption and data retrieval. Therefore, we propose a novel blockchain-assisted multi-keyword searchable encryption scheme (BAMKSE) that utilizes the decentralized nature of blockchain to overcome these limitations. This scheme integrates ciphertext policy attribute-based encryption (CP-ABE) with key policy attribute-based encryption (KP-ABE) to provide advanced access control and mutual authentication, while offloading the computational burden of decryption to cloud-based pre-decryption services. Security analyses demonstrate the resilience of BAMKSE against chosen keywords attacks (CKAs) and chosen-plaintext attacks (CPAs), offering an effective solution for secure and efficient IoT data handling.