Steganography—the practice of concealing data within a carrier—may be used to obscure malicious or criminal information and activity from law enforcement. While steganography dates to the fifth century BC, it has long been regarded as, and remains, one of the most advanced forms of clandestine communication. In modern usage, the Internet allows accessibility to, and broad dissemination of, steganography tools, and its application continues to evolve with technology. Understanding steganography in its current state is essential to its identification and detection.