A novel CLWE-based attribute-based encryption scheme from lattices with privacy preserving

Abstract Lattice-based attribute-based encryption (ABE) combines the advantages of against quantum attack and fine-grained access control. However, most existing LWE-based or RLWE-based ABE schemes from lattices have the limitations of large storage cost and lack of support for attribute privacy protection. In 2022, a new algebraically structured LWE variant-cyclic algebra LWE (CLWE), was proposed by Grover et al. in journal of cryptology (JoC). This new variant has its inherent storage and computing advantages, especially in reducing the storage overhead. Therefore, to reduce the storage cost and protect the attribute privacy, we propose a novel lattice-based ABE scheme based on CLWE. More specifically, by introducing an extended Shamir’s secret sharing scheme on cyclic algebra and a two-dimensional (attribute label, attribute value) attribute structure, we extend the CLWE-based PKE scheme in JoC22 to a CLWE-based ABE scheme. The sizes of public key, master secret key, user’s secret key and ciphertext of our proposal are remarkably reduced. In addition, we combines a semi access policy structure and the two-dimensional attribute structure to hide the user’s attribute values, thereby preventing the leakage of user attribute privacy. Performance analysis shows that compared related lattice-based ABE schemes, our proposal is more efficient in the storage cost and it supports attribute privacy protection. Finally, our scheme is proved to be secure in the standard model.