LDPC based image authentication system

Today, with the increasing use and easy manipulation property of digital images, it is obviously that digital images captured from CCD cameras or other digital image devices have to be analyzed and determined before process it. To keep the integrity and ensure the accuracy and reliability of the digital image, we need some sort of robust methods and standard procedures that guarantee the strengthen authenticity of digital image. image authentication is a technique that analyze a digital image and determine if it has been altered. Image authentication technique can be used for various organizations such as health care organizations, law enforcement agencies and insurance companies etc. Image authentication is also important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. untrusted intermediaries might tamper the contents of image. Distinguishing the legitimate diversity of encodings from malicious manipulation is the challenge addressed in this paper. We developed a LDPC based new approach for image authentication. With the help of this approach we can authenticate image effectively. In our technique, we provide LDPC quantized image projection and the Encrypted image digest as authentication data. These data can be correctly decoded only with the help of an authentic image as side information. This technique provides the desired robustness against legitimate encoding variations, while detecting illegitimate modification.