Definitions for "Steganography"
The art of writing in cipher, or in characters which are not intelligible except to persons who have the key; cryptography.
The branch of cryptography in which messages are hidden inside other messages; -- used commonly for the process of hiding messages inside a computerized image file, as for example hiding the name and copyright notice of the owner of an image as protection against violation of the copyright.
Art and science of conveying information in such a way that its presence is unnoticed. It comes from the greek words steganós steganos (covered) and graptos graptos (writing), literally covered writing, in the sense of a hidden thing. In steganography the text or image in question is invisible although it resides in the interior of an apparently normal piece of other information, like a text an image or a soundtrack. Unlike cryptography where the message is clearly visible although you need the key to decipher it, in this case the information cannot be seen unless the correct procedure is applied to the text or image where it resides.
Keywords:  attenuator, stem, stepped
Stem Stepped Attenuator