Multi-User Revocable Keyword Search Scheme for

With the rapid development of cloud computing, more and more users store their data in the cloud. Considering the privacy problem of the data sharing in the cloud, searchable encryption makes it possible to efficiently share and retrieve data in multi-user settings. The existing keyword search scheme of sharing the private key with authorized users to generate trapdoors may increase the risk of key exposure, and the scheme of encrypting the data with the secret key of each authorized user and generating a ciphertext for each user may not be suitable for data sharing between a large number of users. In this paper, we combine the secure IBBE system with the keywords search and propose the scheme to achieve safe and efficient multi-user data sharing in the cloud. Authorized users can perform keyword search directly on encrypted data without sharing the secret key, and for a shared file, the data owner only needs to encrypt one ciphertext for all authorized users. Besides, authorized users of shared files can be revoked. User authorization tables and IBBE ensure that revoked users cannot access files.