Echo Hiding Technology

Information hiding is a technology which embeds the important data in to the digital audio, picture or video to hide the existence for copyright identification or undercover communication. Echo hiding is an important branch of the information hiding based on audio signals.This paper firstly introduces the concept, principle and characteristic of echo hiding, and analyzes its current situation, developmental trend and the key research points. Thereafter, an adaptive algorithm of echo hiding based on short-time energy computing. The original audio is first divided into segments, and the energy of each segment is computed. The decay rate of echo kernel is adaptively adjusted according to each segment's energy. By adaptively adjusting the decay rate of each segment, a significant improvement in audio quality is achieved. The proposed method is robust to many attack operations, such as noise addition, filter, resample, MPEG3 coding/decoding, and so on.On the basis of investigating the affection of the error correction codes on improving information detection efficiency, this paper introduces the BCH code into the echo hiding, which can decrease the error rate of the information detection and improve the robust ability of the algorithm evidently. Subsequently, several principles are given on how to use error correction codes more efficiently.Synchronization is one of the key issues of information hiding based on audio signals. The current audio information hiding algorithms lack effective techniques for synchronization. This paper also analyzes the causation of the synchronization problem, and gives a summarization of the methods of working for resolving the synchronization problem. On the basis of this, a novel method of echo hiding is proposed, which based on speech signal's character points' extraction. Experiments show that the method has a fine ability to stand against the synchronization attack, such as random cropping.