Research On The Method Of Security Protection For OOXML Document Based On Multiple Digital Watermarking

OOXML is a type of technical specification applied for Microsoft Office 2007 and later products,which has been using widely in recent years.However,in some occasions with high security requirements,OOXML documents have obvious flaws,such as copyright judgment,integrity verification,confidential content access control,and so on.These issues of information security have attracted considerable interest from scholars at domestic and abroad.In terms of the security protection of OOXML documents,there are some deficiencies in traditional digital watermarking and document encryption methods.On the one hand,the watermark function is single,embedding capacity is less,and the concealment,robustness and security need to be improved.On the other hand,the encryption algorithm is only for the entire document,and the security overhead is large,but now we are paying more attention to the access control of partial confidential data.To solve the above problems,this paper provied a method of security protection of OOXML documents based on multiple digital watermarks.This method can effectively protect the copyright of documents,verify the integrity of the content,perform tamper detection and location,and achieve fine-grained access to confidential data.The innovation of this method lies in the combination of multiple digital watermarking schemes and sticky policy access control models,which realized hierarchical access to documents and forensic traceability after data leakage.The main research results of this paper are as follows:(1)Design a multiple digital watermarking scheme which consists of four watermarks.Firstly,in the document.xml,the fragile watermark of the content field is embedded by text segmentation.Secondly,the fragile watermark of the format field is embedded by replacing the last six bits of the identifier w:rsidRPr.Thirdly,in the settings.xml,the robust watermark is embedded by adding the w:rsid attribute and its attribute value.Fourthly,a zero watermark is constructed by analyzing Chinese character strokes.At the same time,a watermark identifier is added at the position of the text segmentation,the position where the modified identifier is replaced,and the position where the redundant attribute is added,which is convenient for accurate positioning when the watermark is extracted.Finally,the watermark information is extracted to verify the copyright and integrity of the document,meanwhile,Hamming code correction,tamper detection and location are performed according to the actual situation.(2)Build a document access control model based on sticky policy.Firstly,data is classified through data segmentation algorithm according to the degree of content confidentiality,and then,the data fragment set is encapsulated and the user's document access authority is established.Secondly,design a corresponding sticky policy for each level of data and embed it in the OOXML document document.xml component.When the user initiates an access request,the access control algorithm is implemented to achieve permission access to the document;Finally,in the newly generated document view,the unique identifier of the visitor is embedded by using the digital watermark technology in order to verification of document integrity and forensic tracing.