Revocable cloud data security sharing method

TL;DR: In this paper, a revocable cloud data security sharing method was proposed, where the data owner can safely share the data stored in the cloud with other users, and meanwhile, part of shared users can be efficiently cancelled according to the requirements of the owner.

Abstract: The invention discloses a revocable cloud data security sharing method. The method comprises the following steps: a cloud server generating a public parameter and a main key of a system; the cloud server generating a corresponding private key for each user id; the data owner encrypts the data M required to be shared into a ciphertext C and uploads the ciphertext C to the cloud server; the data owner generates a shared key for the initial shared user list S and uploads the shared key to the cloud server; the cloud server receives a to-be-cancelled shared user list R from the data owner to obtain a new shared user list S'= S-R, generating a new shared key corresponding to the shared user list S'; The cloud server generates a ciphertext CT of the shared user according to the ciphertext C andthe current shared key; and downloading the ciphertext from the cloud server by each user, and decrypting by using the private key to obtain the data M. Through the method and the system, the data owner can safely share the data stored in the cloud with other users, and meanwhile, part of shared users can be efficiently cancelled according to the requirements of the owner.