Research On Anti-counterfeiting Application Of Certificate Based On Anti-copy Technology And PDF417 Code

Credentials are certificates and documents used to prove identity,experience,etc.Because of its low cost and convenient use,paper has always been an important carrier for various types of documents.With the development of information technology,more and more documents have begun to be electronicized and applied to real life.However,the current system of electronic inquiry in China is not complete enough,which has led to common occurrences of criminals forging other persons' documents for profit.Therefore,it is urgent to take strong measures to realize the integration of human and document in document verification.So far,there are mainly two ways of anti-counterfeiting for paper certificates.One way is to use special materials to make certificates.Due to the particularity of the materials and the confidentiality of the production process,it is difficult for criminals to forge real certificates.However,this method has a high production cost and is not practical for ordinary paper certificates.Another way is to add a two-dimensional code in the certificate and scan the two-dimensional code information during verification and compare it with the information in the database to determine whether it is an original.This way relies on computers and the Internet,and will not be able to use when there is a fault.Therefore,this dissertation proposes a three-layer security scheme for certificates based on anti-copy technology and PDF417 code watermark technology,which not only reduces the production cost,but also meets the security needs of ordinary certificates,and can be operated offline.Based on the watermarking algorithm,a mobile APP is also developed for the convenience of users.Firstly,the author designs a security pattern.Through the analysis and research of the existing anti-copy technology,a low-cost,good-effect copy-proof graphic technology is chosen.Based on this,a new type of anti-copy pattern is designed.Patterns are visible when printed,but disappear when photocopied,so as to achieve the effect of anti-copying.Secondly,a digital watermarking algorithm based on PDF417 code is designed.After encoding watermark information into a binary sequence,according to the existing anti-print scan watermarking algorithm,the appropriate boundary of the PDF417 code is selected.Then,the pixels are flipped according to the watermark information sequence.By adjusting the PDF417 code bar width,the watermark information is embedded into the PDF417 code.Image correction steps are added before watermark information extraction to meet the needs of mobile phone camera.Through the above steps,the watermark information can be extracted by mobile phone.Finally,an APP,corresponding to the watermarking algorithm,is developed through the android development platform.Users can use this APP to extract watermark information and read QR code information.Comparing watermark information with copyright holder information.The information extracted from the PDF417 code is compared with the information of the copyright owner so as to achieve the purpose of the second level of anti-counterfeiting.The third level of anti-counterfeiting is achieved by comparing the PDF41 7 code information with the core copyright information.The experimental results show that the anti-counterfeiting scheme composed of the anti-copying pattern and PDF417 code can achieve the best performance when the background circle has a gray level of 170 and the background circle radius is 7.The original and the copy documents can be quickly identified.The PDF417 code breaks the shackles of the original algorithm.Even when the bit error rate to be less than 20%,the watermark information can also be decoded,which basically realizes the mobile phone's camera recognition function.The APP designed in this dissertation basically fulfills the requirements for anti-counterfeit verification of mobile phone certificates,and can meet the needs of practical applications.