Fair and Exculpable Attribute-Based Searchable Encryption With Revocation and Verifiable Outsourced Decryption Using Smart Contract

Users are inclined to outsource their data to the cloud due to the rapid growth of data in response to the growing use of cloud computing and the Internet of Things (IoT). One of the primary issues for users is the secure sharing of personal data. Access control and fine-grained sharing of encrypted data can be accomplished with attribute-based encryption (ABE). However, the computational cost required for ABE decryption hinders its widespread deployment on lightweight devices. For lightweight mobile devices, outsourcing computation is a highly attractive technical that outsources heavy decryption tasks to the cloud. The majority of current outsourced ABE schemes, however, only verify whether the cloud returns the correct decryption result, and lack a mechanism to prevent mobile devices from maliciously accusing the cloud of returning incorrect results, and overlook fairness between mobile devices and the cloud. Furthermore, the increasing number of encrypted files stored in the cloud will impede efficient query processing. Moreover, attribute revocation and privacy protection are also crucial. Therefore, this paper proposes Fair and Exculpable Attribute-Based Searchable Encryption with Revocation and Verifiable Outsourced Decryption (FE-ABSE-RV) Using Smart Contract, and constructs a concrete FE-ABSE-RV scheme. The scheme is capable of withstanding chosen plaintext attack and chosen keyword attack according to security analysis. Theoretical analysis and simulation experiments illustrate that the FE-ABSE-RV scheme is more expressive, efficient, and practical.