A Hybrid Attribute-Based Encryption Scheme for Cloud Storage: Integrating Lattice-based Cryptography and Symmetric Block Ciphers

In the era of cloud storage and computing, Attribute-Based Encryption (ABE) has emerged as a promising technology for fine-grained access control of data. However, it faces significant challenges in terms of both performance and security. On one hand, traditional ABE schemes often suffer from high computational complexity, leading to slow encryption and decryption processes, which cannot meet the real-time requirements of cloud services. On the other hand, with the rapid development of quantum computing, the security of existing ABE schemes based on traditional cryptographic assumptions is at risk, as quantum algorithms may potentially break these schemes in polynomial time. Therefore, it is crucial to design an ABE scheme that can not only improve performance but also resist quantum threats. To tackle the performance bottlenecks and security vulnerabilities of ABE in cloud storage and computing settings, this paper proposes a hybrid ABE approach that integrates latticebased cryptography and symmetric block ciphers. In this scheme, symmetric block ciphers are employed to quickly encrypt user data, while lattice-based cryptographic primitives are used to construct quantum-resistant digital envelopes. Specifically, lattice-based Key Encapsulation Mechanisms (KEMs) generate digital envelopes to ensure the confidentiality of symmetric keys. This hybrid design strikes a balance between efficiency and security. Symmetric block ciphers can achieve encryption at a much faster rate compared to pure lattice-based ABE schemes, and there is currently no known quantum algorithm capable of breaking standardized block ciphers within polynomial time. Additionally, lattice cryptography provides protection against quantum attacks on public-key components, enhancing the overall post-quantum security of the scheme without compromising its performance.