Abstract: With the rapid development of information technology, a large number of confidential e-documents are stored in computers, which are prone to leakage due mainly to negligence. Surveys show that up to 90% of the companies face severe financial risks because of data loss. This paper proposes a scheme to prevent e-documents from accidental leaking. This is achieved by embedding watermarks into confidential e-documents. For Microsoft Word files, the watermarks are embedded using specially designed plugins. Confidential documents that carry watermarks are intercepted at the gateway by a watermark detector implemented either with software or hardware.

Key words: electronic files, leaking, digital watermarking