1. A system, comprising: a storage system; and at least one processor to execute one or more programs stored in the storage system, the one or more programs comprising: a detecting module operable to detect a file copy operation indicative of a file being copied to an electronic clipboard of the system; a converting module operable to read file contents of the copied file listed in the electronic clipboard, and scramble the file contents using an arithmetic method, wherein file attributes of the scrambled file are the same as file attributes of the copied file, and the file attributes of the copied file comprise a file size, a file format, a file name, and a file path in the system; the detecting module also operable to detect a file paste operation indicative of the copied file being paste to a designated file system path; and an executing module operable to paste the scrambled file to the designated file system path, and to store the file name and the file path of the copied file into a copied file list stored in the storage system.