Traceable and Revocable Attribute-Based Conjunctive Keyword Search

The Attribute-Based Keyword Search (ABKS) scheme provides a secure, efficient, and expressive method for data outsourcing to the cloud, offering fine-grained access control to prevent unauthorized data usage. However, existing ABKS schemes primarily cater to the single-owner model and lack effective mechanisms to trace or revoke access from malicious users who leak decryption keys. In this paper, we introduce TR-ABCKS, a traceable and revocable attribute-based conjunctive keyword search scheme. Designed for the multi-to- multi model, TR-ABCKS supports conjunctive keyword search and features an efficient revocation mechanism utilizing binary trees with multilinear maps to revoke access permissions from malicious users. Additionally, TR-ABCKS achieves white-box traceability, preventing malicious users from leaking decryption keys for economic gain. Our comprehensive security analysis confirms TR-ABCKS's semantic security, validated by experimental simulations, showcasing its effectiveness.