Research On Searchable Encryption Based On The SM9 Algorithm

The rapid development of the Internet has been accompanied by a rapid increase in data volume.Users have an increasing demand for computing power and storage space,leading to a large amount of local data being encrypted and uploaded to cloud servers for storage.However,in traditional encryption systems,users are unable to directly search encrypted data;they must decrypt it before performing searches.To enable efficient retrieval of encrypted data in the cloud while ensuring the security of the original plaintext,searchable encryption technology has emerged.Public key searchable encryption,as one form of searchable encryption,encrypts keywords using a public key.Users who possess the corresponding private key generate trapdoor and upload them to the cloud server.The cloud server performs ciphertext retrieval and matching based on the trapdoor.Currently,most public key searchable encryption schemes rely on foreign cryptographic algorithms.To reduce excessive dependence on foreign information security technology products and achieve secure and independent control,it is of significant theoretical and practical value to design a secure and efficient searchable encryption scheme based on our China’s commercial cryptography SM9 standard.Starting from the national commercial SM9 cryptographic algorithm,this paper deeply studies the searchable encryption scheme based on the china state cryptography standard SM9.The details are as follows:(1)Aiming at the issues of adaptive chosen keyword attacks and low retrieval efficiency in searchable encryption schemes,this paper proposes an identity-based searchable encryption scheme based on the core technologies of SM9 algorithm.The proposed scheme solves the certificate management problem of traditional public key searchable encryption under the identity-based encryption system.Additionally,the private key used in this scheme is the same as the one used in the China State Cryptography Standard SM9 algorithm,enabling data encryption to be performed using the private key and reducing the cost of key management.The scheme also improves system efficiency and security through its ciphertext retrieval functionality.Security proofs demonstrate that,under the assumption of q-BDHI,the proposed scheme achieves indistinguishability against adaptive chosen keyword attacks.Performance analysis demonstrates that the proposed scheme has lower computational and communication costs compared to related schemes.(2)Aiming at the issues of offline keyword guessing attacks and low efficiency of single keyword retrieval in searchable encryption schemes,based on BLS signature technology and the SM9 algorithm,this paper proposes a server-assisted certificate-based multi-keyword searchable encryption scheme.The proposed scheme introduces an auxiliary server to resist offline keyword guessing attacks and utilizes a multi-keyword encryption mode to improve retrieval efficiency.Additionally,the scheme resolves issues related to certificate management,key escrow,and secure channels.Security proofs demonstrate that,under the q-BDHI assumption and the CBDH assumption,the proposed scheme achieves indistinguishability against adaptive chosen keyword attacks and adaptive keyword guessing attacks,respectively.Performance analysis demonstrates that the proposed scheme has more advantage in terms of computational and communication costs compared to related schemes.