A revocable cloud data security sharing method

Abstract

The invention discloses a revocable cloud data security sharing method, the steps are: the cloud server generates the public parameters and the master key of the system; the cloud server generates the corresponding private key for each user ID; the data owner will need the shared data M is encrypted into ciphertext C and uploaded to the cloud server; the data owner generates a shared key for the initial shared user list S and uploads it to the cloud server; the cloud server receives the shared user list R that needs to be revoked from the data owner, Obtain the new shared user list S'=S-R, and generate a new shared key corresponding to the shared user list S'; the cloud server generates the shared user's ciphertext CT according to the ciphertext C and the current shared key; each user Download the ciphertext from the cloud server, decrypt it with the private key, and obtain the data M. Through the present invention, the data owner can safely share the data stored in the cloud with other users, and at the same time can efficiently revoke some sharing users according to his own requirements.

Description

technical field [0001] The invention belongs to the fields of information sharing and information security, and in particular relates to a revocable cloud data security sharing method. Background technique [0002] With the development of cloud technology, more and more users, enterprises, and scientific research institutes save their information in the cloud. When cloud computing provides users with convenient data services, it also brings about the problem of user data security. In order to protect the security of user data, user data is usually encrypted locally and then stored in the cloud. When user data is encrypted and stored in the cloud, users often need to perform certain operations on the data, and data sharing is the most common operation. However, due to encryption, the user's data loses its original structure, and the cloud server's data sharing operation also becomes invalid. Existing cloud data security sharing methods are mainly based on proxy re-encrypti...

AI Technical Summary

Problems solved by technology

There are two problems in these methods: (1) the data owner needs to generate a new shared key in each new time period, and the calculation amount of the new shared key is often relatively large; (2) the data owner needs to generate a new shared key every time. After generating a new shared key each time, a secure channel is required to send the shared key to the cloud server, and the cost of establishing a secure channel is often relatively high

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