Key encryption method based on file attribution

Abstract

The invention discloses a key encryption method based on file attribution. The key encryption method comprises the following steps of: receiving a user file, generating an attribution aggregate, an access structure tree, a main key and a public key according to the user file, randomly generating symmetric keys, encrypting the user file by using the symmetric keys and a symmetric encryption algorithm to obtain data cipher text, encrypting the symmetric keys by utilizing the public key and the access structure tree to generate a key cipher text, generating a private key associated with the attribution aggregate by utilizing the main key and the attribution aggregate, transmitting the key cipher text and the data cipher text to a server to store, obtaining the key cipher text and the data cipher text from the server by a user, decrypting the key cipher text by using the private key by the user to judge whether the attribution aggregate associated with the private key meets the access structure tree or not, and if meeting the access structure tree, decrypting the symmetric key and decrypting the data cipher text by utilizing the symmetric key through the user to obtain plaintext data. According to the key encryption method based on the file attribution, disclosed by the invention, data is encrypted by the symmetric encryption algorithm, the safety of the symmetric key is protected based on attribution encryption, and the high-efficiency safe access of encrypted data is realized.

Description

technical field [0001] The invention belongs to the field of computer security, and in particular relates to a key encryption method based on file attributes. Background technique [0002] In cloud storage, since the data is in a domain beyond the user's control, in order to protect the privacy of sensitive data, the data is usually encrypted first to protect the security of the data. But at the same time, it brings new challenges - due to the unfixed decryption party users in the distributed environment, the diversity of data file types and sizes, the use of traditional symmetric encryption is not safe, and the use of traditional public key cryptosystem encryption is not efficient. At the same time, in order to protect the privacy of the shared data, the user needs to implement an access control policy for the ciphertext. For example, he can define a policy that only personnel above the level and with administrative authority can access a certain top-secret document. The ...

AI Technical Summary

Problems solved by technology

The disadvantage is that both the sending and receiving parties must use the same key, and use the unique key that others do not know, so the security of the key cannot be guaranteed, so it is difficult to use the symmetric encryption system on the distributed file storage system

This organization issues public key certificates for each user in the system, so CA needs a lot of time and storage space to issue and store user certificates and public keys in encryption applications, and user verification certificates are also cumbersome. Less efficient on the storage system

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