Untraceable Steganography: Towards the Anonymity of Steganographer

Abstract

To protect sender's identity of covert communication, this paper proposes a new concept of steganography called untraceable steganography. The receiver can extract secret data from stego media without knowing who was the sender. Specifically, the stego media is produced by a number of individuals (including the sender and other normal individuals). Thus, the receiver cannot know who was the sender, since the media produced by the sender is only a part of stego media and the receiver cannot find the part produced by the sender from stego media. Therefore, the sender is anonymous during the whole process of steganography. That means this kind of steganography is untraceable. In this case, the sender's identity can be protected, and thus the security of steganography can be advanced in a higher level. A specific untraceable steganography scheme is designed in this paper for digital images, which achieves the function of untraceable steganography without decrease the undetectability of stego media.