A Novel Approach for Extended Insertion-Capacity and Encrypted- Robust Blind Watermarking for Still Images in the DCT Domain

Abstract: This paper presents a novel algorithm for blind watermarking still images in the DCT domain with advanced features. Nine AC values will be modulated to implant an encrypted watermark. Eight of them represent one byte of the useful data to be hidden and the ninth bit represents a key that will be used to scramble the message. Hence, the capacity of insertion is increased by 60% while preserving the imperceptibility criterion. The watermark cannot be hacked because it is scrambled using an individualized key of almost random length and type, hence high level of security. The simulation results reveal satisfactory performance of the algorithm and an acceptable PSNR and limited blocking artifacts. This paper presents a novel algorithm for blind watermarking still images in the DCT domain with advanced features. Nine AC values will be modulated to implant an encrypted watermark. Eight of them represent one byte of the useful data to be hidden and the ninth bit represents a key that will be used to scramble the message. Hence, the capacity of insertion is increased by 60% while preserving the imperceptibility criterion. The watermark cannot be hacked because it is scrambled using an individualized key of almost random length and type, hence high level of security. The simulation results reveal satisfactory performance of the algorithm and an acceptable PSNR and limited blocking artifacts. Key-Words: Blind Watermarking, DCT Domain, Encryption, Watermark Scrambling, AC Coefficients, Security.