Context-Aware Encrypted Query Processing with Progressive Security-Enabled Cloud Systems

Ciphertext-Policy Attribute-Based Searchable Encryption (CP-ABSE) is considered highly effective for cloud environments due to its fine-grained access control and ability to retrieve keywords from encrypted data. However, existing CP-ABSE schemes face significant challenges in ensuring forward security and enabling secure data deletion without depending on the cloud provider. To address these issues, we propose a Puncturable CP-ABSE (Pun-CP-ABSE) scheme, which supports self-controlled, fine-grained data deletion within a searchable encryption framework. In this scheme, the data owner can “puncture” the trapdoor to delete data securely, eliminating the need for a trusted third party while ensuring forward security. Once the trapdoor is punctured, the cloud server loses the ability to search the related ciphertext. Additionally, we demonstrate that the Pun-CP-ABSE scheme is secure against both Chosen-Plaintext Attacks (CPA) and Chosen-Keyword Attacks (CKA). We have also developed a practical implementation of Pun-CP-ABSE to validate its performance and real-world applicability.