history of steganography before computers

In this two-step, numeric form, no normal human would ever be able to decrypt our secret message at glance. This new algorithm would turn Emsisoft Rocks into two numbers:

For example, after shifting each letter to the letter that comes before it, we could then convert each letter to its numeric equivalent, such that A=01, B=02, C=03, etc. To conceal our message better we could create a more complex algorithm, by adding another step. If we wanted to cryptographically transmit this message we could instead write:Ĭoncealed by a simple algorithm (each letter becomes the letter that comes before it in the English alphabet) we could now spread this message to others, and only those who knew how to decrypt it could read it.Ī one letter shift is really quite simple, though. As an example, consider the following message: Today, digital steganography takes roughly the same approach as the Ancient Greeks: secret things are hidden by other things that aren’t so secret. Steganography, on the other hand, intentionally conceals its concealment, so as not to arouse suspicion. While cryptography hides secret information, it does so in an obvious manner that is to say, when you see it, you know something is going on. In this way, steganography differs from cryptography – another term you might have heard thrown around the malware scene (and also one of Grecian origins). In both of these ancient examples, and in fact in all instances of steganography, the subterfuge depends upon hiding something secret with something that is not. Upon arrival, their head would be shaved. They would then wait for their hair to grow back to conceal the information, and then simply transmit the message in plain sight. In other instances, messengers would have the secret message tattooed on their scalp. Upon delivery, the beeswax would be peeled away and the true message – perhaps a military maneuver – would be revealed. As early as 440 BCE, messengers would conceal important information scribed on wooden tablets by covering it with a layer of beeswax that contained a different, nonsecret message. Today, steganography is defined as “the practice of concealing messages or information within other nonsecret text or data.”īefore computers – and in fact before the word was even made up – physical steganography was employed by the Ancient Greeks to send secret messages. First used in 1499 by German cryptographer Johannes Trithemus, the term actually borrows from ancient Greek, combining the words steganos (concealed, protected, covered) and graphein (writing).

History of steganography before computers