Steganography involves the hiding of messages in plain sight. If you wanted to send a message to someone without arousing suspicion, you would use steganography.
Related post: StegaSpider Surveillance System
Illustrated example of steganography
To explain steganography, let’s use an example.
Alice is coordinating an attack on a local bank. She needs to get a message out to some of her supporters, Bob and Carol. Unfortunately, she is already under surveillance by Eve, a law enforcement officer. In order to evade detection, she must send her supporters a message without Eve suspecting anything.
She posts what seems to be a harmless photo on her Facebook profile of a spider she found in her basement. The photo is publicly available for every one to see, so Eve cannot know who will access it.
Unknown to Eve, however, is that Alice has used a “steganography program” to insert another message into this photo. The photo has embedded within it meeting instructions, building plans and notes on an explosive device. Bob and Carol only need to use the same steganography program that Alice used to extract this secret message.
Bob and Carol extract a secret message from the inconspicuous photo using steganography software. Eve is not even aware that Alice has sent out any incriminating materials. The process of sending secret messages in an inconspicuous medium is called steganography.