Now days, the digital cameras have single CCD or CMOS sensor and use color filter array (CFA). Generally the CFAs have RGB color filters placed at top of each sensor element, a single color sample is recorded at each pixel location, while the remaining two color samples are needed to be estimated the neighboring samples. The process of estimating this missing color samples is called as CFA interpolation. In each color channel a correlation exists between subset of pixels which is induced due to color filter array interpolation. The color filters in a CFA are arranged in a periodic pattern, these correlations are periodic. As these correlations are periodic in nature they can be regarded as unique correlations can be used as a type of digital signature-Now days, the digital cameras have single CCD or CMOS sensor and use color filter array (CFA). Generally the CFAs have RGB color filters placed at top of each sensor element, a single color sample is recorded at each pixel location, while the remaining two color samples are needed to be estimated　the neighboring samples. The process of estimating this missing color samples is called as CFA interpolation. In each color channel a correlation exists between subset of pixels which is induced due to color filter array interpolation. The color filters in a CFA are arranged in a periodic pattern, these correlations are periodic. As these correlations are periodic in nature they can be regarded as unique correlations can be used as a type of digital signature