Authentication of images through non convoluted DCT (AINCDCT)

In this paper a DCT based gray scale image authentication technique in frequency domain, termed as AINCDCT has been proposed. The cover image transformed into the spectral domain through 2 × 2 mask in row major order using nonconventional DCT, resulting corresponding frequency components. Higher frequency components having less energy, replaced by secret bits using secret key and a hash function. Reverse procedure is followed during decryption. Experimental results obtained compared with the existing authentication techniques Luo et al and WTSIC in terms of Mean Square Error (MSE), Peak Signal to Noise Ratio (PSNR) and Image Fidelity (IF) which show better performances in AINCDCT.