Toward Construction-Based Data Hiding: From Secrets to Fingerprint Images

Data hiding usually involves the alteration of a cover signal for embedding a secret message. In this paper, we propose a construction-based data hiding technique which transforms a secret message into a fingerprint image directly. Unlike the conventional data hiding techniques, this scheme does not need any cover signals to participate. Instead, it generates the fingerprint image based on a piece of hologram phase constructed from the secret message. The hologram phase consists of the spiral phase and the continuous phase. First, we propose to map the secret message to a polynomial and encode it into a set of points with different polarities, from which the spiral phase is computed and constructed. Then, we construct the continuous phase by decomposing a fingerprint image synthetically generated. The spiral phase and the continuous phase are combined to form the hologram phase. This is eventually used to construct a fingerprint image in a common form such as the grayscale fingerprint image, binary fingerprint image, or thinned fingerprint image. The secret message can be extracted by detecting the encoded points in the constructed fingerprint. We conduct the experiments by constructing fingerprint images with ordinary sizes, the results show that the secret message can be extracted accurately. It is also difficult to detect the existence of secret message from the constructed fingerprint images.