Puncturable Attribute-Based Encryption From Lattices for Classified Document Sharing

The country’s governmental agencies bear the responsibility for overseeing and executing a wide range of national policies and initiatives, formulating pivotal determinations aimed at safeguarding national security and fostering long-term progress. Most of the decisions are highly confidential, encrypted and transmitted to diverse administrative regions, sectors, and individuals to facilitate execution. Hence, governmental agencies must formulate fine-grained access policies that support secure one-to-many document sharing. However, if the receivers’ keys were exposed, it could result in unauthorized access to document contents, posing a significant threat to national security. When facing keys exposure scenario, addressing the challenge of preventing document content theft while maintaining document archiving for convenient accountability becomes a complex and demanding task. To tackle the above issues, we propose an innovative lattice-based puncturable ciphertext-policy attribute-based encryption scheme. This scheme supports secure one-to-many document sharing, fine-grained access control, and empowers receivers to revoke the decryption capability for specific data according to their own choice after reviewing documents, thereby achieving dual-layer protection for documents. Our scheme has exhibited resilience against quantum attacks, chosen plaintext attacks and collusion attacks.