关键词: 相机, 数字图像取证, 图像源辨识, 传感器模式噪声, 反取证, 反－反取证

Abstract:

Considering the image source identification algorithm based on the camera fingerprint and the imaging sen-sor pattern noise to be easily attacked by fingerprint- copy operation,this paper simplifies the triangle test algorithmwhich is a counter- attack algorithm against the fingerprint- copy operation,that is,the attenuation factor for eachblock is set as a constant,thus reducing calculation time.Then,the performance of the counter- attack algorithm isdiscussed in detail from four aspects,namely,the addition manner of sensor pattern noise,the image content,theway of extracting sensor pattern noise and the number of illegally- used images.Finally,according to the experimentalresults,this paper points out that all the four aspects can affect the success rate of the counter- attack algorithm.Inaddition,the degree and scope of effect caused by the above- mentioned factors are also explored.

Key words: cameras, digital image forensics, image source identification, sensor pattern noise, counter- forensics, counter counter- forensics