File encryption and decryption method, device and system

The embodiment of the invention provides a file encryption and decryption method, device and system. The method comprises the following steps: acquiring a security level encryption file; acquiring the security-level encrypted file by encrypting an encrypted file through a security-level public key; verifying the security-level encrypted file according to the security-level encrypted file abstract in the file meta-information in the data bus; wherein the file meta-information is information for describing the attribute of the security-level encrypted file; and if the security-level encrypted file passes the verification, obtaining an encrypted file corresponding to the security-level encrypted file, and decrypting to obtain a plaintext corresponding to the encrypted file. In the embodiment of the invention, the data bus is adopted to store the file meta-information of the security-level encrypted file, so that the control of file access can be realized, and the security of file access is improved. 本发明实施例提供了一种文