File secure sharing method and system based on group key

Abstract

The invention discloses a file secure sharing method and system based on a group key. When a first user terminal shares an original file, the original file is encrypted by use of a work key so as to generate an encryption file, the work key is encrypted by use of the group key so as to generate key cryptograph, and the encryption file and the key cryptograph are uploaded to a shared storage server; a second user terminal downloads a specific encryption file, a key cryptograph associated with the specific encryption file, and a group identification from the shared storage server; and the second user terminal, when determining that the downloaded group identification is the group identification of a group where the second user terminal is located, decrypts the key cryptograph by use of the group key and decrypts the encryption file by use of the work key so as to obtain the original file. According to the invention, the work key is encrypted by use of the group key, the encryption file can be securely and flexibly shared with user controllability and easy key management, and the risk that a user file is leaked in a sharing process is reduced.

Description

technical field [0001] The invention relates to the communication field, in particular to a group key-based file security sharing method and system. Background technique [0002] With the rapid development of Internet applications, the value of user data continues to increase, and users have put forward higher requirements for the security of information services such as cloud storage. How to improve the security of user data and at the same time realize the safe sharing of data has become the current cloud storage The main technical problems faced by services such as . Currently, the main file sharing technical solutions or systems in the industry have the following problems: [0003] 1. A sharing scheme combining clear text with authorized access, [0004] Low security since files are stored in plaintext; [0005] 2. Ciphertext sharing scheme: [0006] 1) Server-side encryption and decryption, there is a risk of server-side key leakage and insufficient user control capa...

AI Technical Summary

Problems solved by technology

Aiming at the problems of insufficient user self-control ability and difficulty in key and shared group management in existing secure storage schemes, it is proposed to use group key to encrypt file key on the basis of traditional file encryption, and group administrators to classify The method of managing the distribution and updating of group keys can realize flexible, user-controllable, and easy-to-manage encrypted file security sharing on the basis of satisfying the storage security of user data files, and reduce the leakage of user files during the sharing process risks of

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