No abstract

As the product of the third information technology revolution, the Internet of Things (IoT) has greatly altered our way of lifetime. Cloud storage has gradually become the best choice for data processing due to its scalability and flexibility. However, the cloud is not a completely trusted entity, such as tampering with user data or leaking personal privacy. Therefore, cloud storage usually adopts attribute-based encryption schemes to accomplish data confidentiality and fine-grained access control. However, applying the ABE scheme to the Internet of Things still faces many challenges, such as dynamic user revocation, data sharing, and excessive computational burden. In this paper, we propose a novel searchable attribute encryption system that replaces the traditional key generation center with consortium blockchain to generate and manage partial keys. In addition, our scheme can perform predecryption operations in the cloud, and users only need to spend a small amount of computational cost to achieve decryption operations. Security analysis proves that our scheme achieves security under both the chosen keyword attack and the chosen plaintext attack. Compared with other schemes, this scheme is more economical in terms of computing and storage.

The development of the Internet of Things (IoT) has been facing severe security threats, and the security and fine-grained access control of data in the IoT is one of the security problems that urgently need to deal with. Attribute-based encryption (ABE) schemes over lattice can not only achieve fine-grained access control but also resist quantum attacks. However, most schemes are single-bit encryption, which is inefficient. In this study, a multibit inner product predicate encryption (PE) scheme over lattice is proposed, which effectively expands the plaintext space. The scheme can realize multibit attribute-based encryption with the hidden access structure for data security in the IoT and support And-gate operation in the access structure with multiattribute. The fine-grained access control of ciphertext data can be realized under the condition of ensuring data privacy. The security of the scheme is based on LWE problem, and it can resist quantum attacks, that is, CPA security under the standard model.