  Steganography is one of the information hiding techniques, which conceals
secret messages in cover media. Digital image and audio are the most studied
cover media for steganography. However, so far, there is no research on
steganography to utilize complex networks as cover media. To investigate the
possibility and feasibility of complex networks as cover media for
steganography, we introduce steganography of complex networks through three
algorithms: BIND, BYMOND, and BYNIS. BIND hides two bits of a secret message in
an edge, while BYMOND encodes a byte in an edge, without changing the original
network structures. Encoding simulation experiments for the networks of Open
Graph Benchmark demonstrated BIND and BYMOND can successfully hide random
messages in the edge lists. BYNIS synthesizes edges by generating node
identifiers from a given message. The degree distribution of stego network
synthesized by BYNIS was mostly close to a power-law. Steganography of complex
networks is expected to have applications such as watermarking to protect
proprietary datasets, or sensitive information hiding for privacy preservation.
