It’s a tradition as constant as the ball dropping in Times Square on New Year’s Eve: the annual round of steganography challenges inside of the National Cyber League (NCL) Cryptography category. Now, you may wonder, “Just why the heck is steganography classified under cryptography?”—which is a good thing to ask, and luckily the answer is a simple one.

Disclaimer

This is not a post about how to recover information being hidden using steganographic techniques, but merely an explanation as to why it is considered cryptography. To learn more about steganography, browse through our Steganography blog category, and also check our page on Cryptography Resources.

A quick recap on what steganography is

Steganography is the art of hiding information and messages inside of something else. When compared to traditional ciphers and encryption algorithms used in cryptography, stenography takes the Russian nesting doll approach to keeping information secret. Why mathematically garble your data to hide it when you can make it look like a dinosaur with a cool top hat? No one is going to think that distinguished dino is of any importance.

Why is it still considered cryptography?

Cryptography at its simplest is the art of hiding communications and information from unwanted eyes, and steganography definitely does that. Steganography is very much its own unique sub-genre in cryptography. (To invoke the analogy of music, traditional ciphers are classical rock, modern encryption is pop, and steganography is some obscure instrumental progressive rock.) Steganography still uses mathematics and algorithms to hide and obfuscate information from unwanted eyes but does so in a much more unique way that borders on being esoteric.

For example, take LSB-based steganography. LSB stands for “least significant bit,” and it merely takes the last bit of every pixel value and stores part of the message in that last bit. This is quite a common way of hiding messages in image files, but when you compare it to either classical ciphers or modern encryption algorithms, like AES, it is just much more creative. (Not to suggest that it didn’t take creativity to accomplish those other algorithms or ciphers!)

The sum of these two paragraphs is simple. Steganography hides data from an untrusted third party, just like any other form of cryptography. The difference is that steganography does it with a bit more gusto.