No, at least, not for cryptographic steganography.  I should say first that steganography is a much slipperier subject than cryptography - it's harder to specify and analyze.  But a spread-spectrum signal need not be any harder to detect than a narrow-spectrum.  A signal that is transmitted at a very low bitrate may be difficult to detect, but even this is not necessarily true.  In steganography, the message is normally hidden inside another message.  The study of analog, technical ways to transmit signals secretly is not really within the purview of steganography - it includes tricks like line-of-sight infrared lasers, transmissions as short, high data rate bursts, and other esoteric tricks.   05:04, Jan 4, 2005 (UTC)