Public Key Authenticated Encryption with Dynamic Search Permission Management and Secure Sharing

ABSTRACT As a fundamental security requirement for trustworthy cloud storage, data confidentiality has become increasingly important with the widespread adoption of cloud services. Public Key Authenticated Encryption with Keyword Search (PAEKS) enables privacy‐preserving search over encrypted data, making it well suited to sensitive data management in collaborative scenarios. In practical applications, enabling the sharing of retrieved encrypted data and dynamic access control in multi‐user collaborative scenarios remains a challenging problem. To address these challenges, we propose a new public key authenticated encryption with dynamic search permission management and secure sharing. Our scheme enables authorized recipients to securely recover the data encryption keys and decrypt the shared ciphertexts. Furthermore, dynamic permission management is achieved through search trapdoor transformation performed by the receiver server, thereby enabling flexible granting and revocation of search capabilities without re‐encrypting the stored data. Security analysis demonstrates that the proposed scheme achieves data confidentiality, integrity, and forward secrecy. Finally, performance evaluation shows that the scheme incurs constant computational overhead.