Public key searchable encryption scheme in blockchain-enabled multi-user environment

Abstract

In order to meet the needs of data security sharing in multi-user environment, a public key searchable encryption scheme supporting one-to-many mode was proposed.Specifically, the data owner could specify multiple users to retrieve the ciphertext by executing the encryption algorithm once, so as to achieve more flexible sharing of ciphertext data.In addition, the specific file encryption key transfer algorithm was designed to ensure that the user could decrypt and obtain the plaintext correctly after retrieving the ciphertext.Combined with the blockchain technology, the smart contract execution detection algorithm was used to ensure the correctness of the retrieval results.In terms of security, based on the decisional bilinear Diffie-Hellman hypothesis and the modified bilinear Diffie-Hellman hypothesis, it was proved that the proposed scheme satisfies the security requirements of keyword indistinguishability and trapdoor information indistinguishability under the random oracle model, and could resist the internal keyword guessing attack.Finally, the proposed scheme and the existing related schemes were simulated by using jPBC cryptolibrary, and the test results show that the proposed scheme has high computational efficiency.

Keywords

• searchable encryption
• multi-user environment
• ciphertext secure sharing
• blockchain
• smart contract