Research On The Application Of Large Capacity Two-Dimensional Code And Watermark Technology In Certificate Anti-Counterfeiting

With the rapid development of Internet technology,some files information acquisition becomes very convenient,resulting in a series of illegal activities which use high-tech equipment,a serious threat to the security of some files information.In recent years,two-dimensional code technology has been widely used in the field of anti-counterfeiting,but because of its coding is openfree,so the anti-counterfeiting performance is not high,and because of the constraints between the two-dimensional code structure,including the information capacity is not large.Digital watermarking technology is an effective way to realize the copyright protection of digital products.Selecting the appropriate watermarking algorithm can also protect the security of file information.Therefore,digital watermarking technology and 2D code technology can be used in the field of anti-counterfeiting,which can improve the performance of security,and can further protect the security of files information and the copyright of digital products.In this dissertation,based on the specific analysis of two-dimensional code codec,the dissertation designs high-capacity two-dimensional code to protect the security of large-capacity files information,and combines digital watermarking technology to further protect the copyright of files information.Firstly,a codec algorithm based on large-capacity long bar two-dimensional code is proposed.The algorithm generates the large-capacity two-dimensional code by encoding the file information by balancing the error correction level and size of the QR code.In addition,the algorithm generates a long bar two-dimensional code and a special scanner for long bar two-dimensional code decoding.Secondly,an LSB spatial domain watermarking algorithm based on long bar two-dimensional code is proposed.The algorithm uses long bar two-dimensional code(RGB image)as the vector image,uses the MD5 algorithm to encode the file information,the MD5 algorithm results as the watermarking information,and generates three watermarking images.The vector image is divided into three layers:R,G,B.The three watermarking images are embedded in three layers by using the LSB spatial domain watermarking algorithm.The Arnold transform image is applied to the R,G and B vector images embedded in the watermarking.Merge R,G,B vector images embedded in the watermarking,complete the watermarking embedding.Finally,two step anti-counterfeiting scheme is proposed.By comparing the watermarking image extracted by the hierarchical layer and the watermarking image obtained by using the MD5 algorithm again to realize the anti-counterfeiting verification,that is the first step of the anti-counterfeiting scheme.By comparing the scanning information of the long bar two-dimensional code and the files information of the generating long bar two-dimensional code,the prompting the juggling function is realized,that is the second step of the anti-counterfeiting scheme.The experimental results show that the LSB spatial domain watermarking algorithm based on long bar two-dimensional code has a good resistance to common attacks such as crop and noise,which indicates that the algorithm has strong robustness.In addition,when the embedded watermarking image is applied attacks which is weak in the LSB spatial domain watermarking algorithm,specially scan the long bar two-dimensional code vector image,which contains the information can still be clearly resolved,through the comparison to achieve prompting the juggling function,that is to achieve the second step of anti-counterfeiting scheme.Through change of watermarking information to prompt whether the file information is tampered with.If the file information is tampered with,prompting the juggling function detects the file information which is changed to the specific content and location,that is the second step of the anti-counterfeiting scheme.So far,the two step anti-counterfeiting scheme proposed in this dissertation greatly plays the two step anti-counterfeiting advantage.