Design And Develop Of Blind Steganalysis System Based On JPEG Images

Steganography and steganalysis, which are very important component of information warfare in the age of the Internet, have great significance for information security. At present, the possibility of using steganography for hostile information transmission by illegal organizations has caused wide public concern. Meanwhile steganalysis has been attached great importance from all sides. Besides, steganography also finds wide application in the field of anti-piracy. Based on the above, we prepared to design and develop a new Blind Steganalysis System Based on JPEG Images with high-performance, extensible, high recognition rate, and greater practical value, which are according to actual requirements of a large-scale Japanese project in author's company.High-performance means a high rate of correct identification with great time efficiency when the system is used to decide whether images contain any hidden information. That's to say, the system should complete the detection correctly as soon as possible. Extensibility refers to that the system can deal with new steganography tools for JPEG images, which is to say, if we provide training sample set with security messages embedded by new steganography tool and establish the corresponding classifier data, the system can identify these non-natural images exactly. Also, the system requires that the classifier data can be continuously accumulated and effectively shared. The usage, preservation, sharing, as well as accumulation of classifier data should obtain flexibility to increase the system's practical value.Based on the above requirements and an overall consideration of recognition rate and time efficiency, this paper presents a arithmetics of JPEG images blind steganalysis using wavelet decomposition, higher-order statistics and Fisher linear discriminant. In this arithmetic, a 2-level wavelet decomposition is used on images and images are characterized based on building higher-order statistical model to obtain feature vector of each image. At last, the two-class Fisher linear discriminant analysis (FLD), a class specific method for pattern recognition, is used to decide whether images contain any hidden message or not. The paper also implents the key steps of prototype algorithm module with C pseudocode, including wavelet decomposition on images and Fisher linear discrimination.According to above arithmetics, this paper proposes a new design scheme of Blind Steganalysis System Based on JPEG Images based on modularization design of classifier data and database technology. The system based on this design scheme not only has good extensibility to handle the new steganography tools for JPEG image, but also be able to accumulate and share the classifier data continuously and effectively, which can extend the system's life cycle. Besides, the system can continuously improve recognition rate and has great practical value.Result of simulational experiment on Jsteg's large-scale training set shows that the system design has achieved expected results with verified rationality and availability. So it well satisfies the design requirements of company's project.