Attribute-based encryption (ABE) is crucial for ensuring data privacy in cloud computing environments, enabling secure storage and sharing of data. However, the rise of quantum processors presents a significant threat to existing cryptographic protocols by potentially compromising security measures such as factoring large integers and computing discrete logarithms. In response, this paper introduces a novel post-quantum attribute-based encryption scheme based on rank metric codes. Unlike previous schemes, our approach simultaneously addresses key challenges such as verifiability, user privacy, and revocability. By leveraging low-rank parity-check codes, our scheme is designed to resist chosen plaintext attacks in the standard model and offers robustness against reaction attacks, including chosen ciphertext attacks. The scheme also accounts for new attack vectors, where an attacker can breach the system by exploiting file search functionalities and logging out. This adds an important layer of complexity to the system's security analysis, considering how attackers can interfere with secure file sharing and access mechanisms.

Keywords: Attribute-based encryption, rank metric codes, user privacy, user revocation, file attack, cloud security.