Definitions
In 2006, the National Science and Technology Council published the Federal Plan for Cyber Security and Information Assurance Research and Development which included a section called “Detection of Hidden Information and Covert Information Flows.” It explores the potential use of stenography for transmitting encoded messages which are extremely difficult to detect without prior knowledge of their existence.
http://www.nitrd.gov/Pubs/csia/csia_federal_plan.pdf
It also gives useful definitions as a starting point for understanding steganography:
The word steganography is derived from the ancient Greek words for “covered writing,” (Hence the similarly named stegosaurus.) See clever graphic below.
Most simply, steganography can be defined as the “art and science of writing hidden messages in such a way that no one apart from the intended recipient knows of the existence of the message.” (NSTC 57)
Other useful terms and definitions include:
Payload: the message to be encrypted
Covert file/Stego: the altered file
Carrier: Original file
Channel: the type imput, ex jpeg
Candidate: a file identified as potentially altered
Suspect: a file containing steg
