Introducing AV1 Codec-Level Video Steganography

Steganography is the ancient art of concealing messages into data. High research interest has grown over the last years, however, techniques in literature are only focused on standard and in some way legacy multimedia formats (e.g., H.264). Moreover, most video steganography techniques are based on concealing data into contents of each frame employing many strategies. In this paper, a codec-level video steganography technique is presented on the novel AV1: a royalty-free video compression format proposed by the Alliance for Open Media (AOM). The proposed method is based on the alteration of intra-prediction angles and, differently from other solutions, it works along the compression process, by allowing the encoder to reduce possible distortions caused by the messages to be hidden. The effectiveness of the technique was demonstrated by hiding up to 1024 characters into an highly compressed video of 40 s maintaining an average Peak Signal-to-Noise Ratio value of 37.53 dB.