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.