PUL-ABE: An Efficient and Quantum-resistant CP-ABE with Policy Update in Cloud Storage

With data being the essential factor of production in the new smart city, the volume of data has exploded. The management and sharing of massive data produced by various industries have become an urgent problem nowadays. Cloud technology facilitates the storage of vast volumes of data and the delivery of precise services upon the requests of users, making it a practical choice for data storage. Data owners can share their data in a flexible and open environment by storing it on a cloud platform. However, the sensitive nature of personal data underscores the importance of ensuring data security and privacy. Attribute-Based Encryption (ABE) is a viable approach to address the above concerns as it supports end-to-end security, one-to-many data sharing and fine-grained access control. In addition, to accommodate significant increase in complexity of data sharing environments and maximize the value of data, data owners will adjust the access policy in real-time based on feedback from data receivers and changes in data usability. The emergence of quantum computers poses significant security challenges to classical cryptographic difficult problems. We first propose a Ciphertext-Policy ABE scheme from lattices that supports access policy update and resists attacks including quantum, collusion, and chosen plaintext.