H.264 Compressed Domain Watermarking in Content Delivery Network (CDN) Environment

Abstract

Over the years it has been observed that a hacker, finds it less difficult to break any encryption key, even though it may require large number of attempts, specially with advent of high-speed machines. Therefore, an encryption method alone is not sufficient for copyright protection and ownership authentication of stored and streamed videos. Digital watermarking techniques have been proposed for this purpose. A fast method of watermarking of streamed H.264 video data is proposed in the present work to meet the real time criteria of a streaming CDN server. The approach involves a blind watermarking scheme that inserts watermark in transformed coefficients of Independent Decoder Refresh (IDR) frames of the streamed H.264. As these IDR frames are then required to reconstruct the P frames, the proposed scheme can ensure security for both type of frames namely I and P. The method also may include a hashing technique to hash the entire group of pictures (GOP) into a 128-bit number. This number, in turn, is used as watermark for the next GOP to ensure the integrity feature of the watermarking scheme.