  Data hiding is the art of hiding secret data into a cover object such as
digital image for covert communication. In this paper, we make the first step
towards hiding ``data hiding'', which is totally different from many
conventional works that directly embed secret data in a given cover object. In
detail, we propose a novel method to disguise data hiding tools, including a
data embedding tool and a data extraction tool, as a deep neural network (DNN)
with an ordinary task (i.e., style transfer). After training the DNN for both
style transfer and data hiding, while the DNN can transfer the style of an
image to the target one, it can also hide secret data into a cover image or
extract secret data from a stego image. In other words, the tools of data
hiding are hidden to avoid arousing suspicion. Experimental results and
analysis have shown the feasibility, applicability and superiority of the
proposed method.
