Dating html codes
To get a feel for these methods, let's take a look at some ciphers. (Actually, substitution ciphers could properly be called codes in most cases.) Morse code, shorthand, semaphore, and the ASCII code with which these characters are being stored in inside my Macintosh are all examples.(ASCII stands for American Standard Code for Information Interchange, just in case you're interested.) The only difference between these and the spy codes is that the above examples are standardized so that everybody knows them.The easier the algorithm you choose, the more often you will have to change the key that unlocks the code - if you want to keep your enemy in the dark.Ciphers are broken into two main categories; substitution ciphers and transposition ciphers.
If you are in the battlefield and are receiving current tactical data, you want an algorithm that makes it easy to decipher the message in the heat of battle.If you don't know Greek (and not many of us do) the above letters could be a form of code themselves!Although the distinction is fuzzy, ciphers are different from codes.When you were a kid, did you have a "Captain Midnight" decoder ring?
With it, you could send messages to a friends that no one else could read.You rotate the outside ring and substitute the letters in your message found on the outside ring with the letters directly below on the inside ring (see diagram).Here, the algorithm is to offset the alphabet and the key is the number of characters to offset it.Or perhaps you remember using special symbols to write notes to your "squeeze" in class.