A Novel Watermark Embedding and Detection Scheme Based on Zero- Knowledge Proof

Abstract

A new watermark embedding and detection method in Microsoft Word 2007-2010 files which use Office Open XML (OOXML) format is proposed in this paper. Watermark information can be imperceptibly embedded into OOXML documents by replacing or adding the values of Revision Identifiers (RIs), which are specific attributes in the main document body of the OOXML document. In the detection process, a secure watermark detection scheme based on zero-knowledge proof is proposed without revealing any watermarking-related information to improve the security of watermarking detection. Experiments show that 4.43 bit is embedded into each word and 0.07 bit is embedded into each bit of the document on average, which is higher than contemporary linguistic watermarking approaches. The method can resist “Format”, “Impersonation”, “Save As”, “Copy” and other active attacks and all these changes will not be shown on the MS Office screen display. Therefore, the proposed method can apply to the field of security protection for OOXML format documents.