How do you create a cypher?

Question

I keep a journal and since there aren't many spots to hide it in a tiny dorm room I want to encrypt it. I don't know much on the subject, but I know there is a type of cypher where a key word is used (the one example I can think of at the moment is from The Prestige (movie, not the book) when the magicians encrypt the secrets to their tricks). How does this work?

Answer 1

I remember The Prestige... awesome movie. Anyway, I also saw that the guy encrypted messages with a keyword. It's most likely a Vigenere Cipher or another similar one which uses a tabula recta.

The Vigenere Cipher works this way: You get your message (suppose it's "hello") and choose a keyword (suppose it's "two"). To encrypt it you need this table (the tabula recta): http://upload.wikimedia.org/wikipedia/commons/c/c7/Vigenere-square.png . You just find where the first letter in the message (H) crosses with the first letter of the keyword (T) and get the letter in the intersection (A). Then you do the second letter in the message with the second in the keyword, third with the third, etc. When the letters in the keyword run out, you just start using it all over again (so the fourth letter in "hello", L, would be encrypted with the letter T). "Hello" encrypted with the keyword "two" would be "axzek".

There is a way to crack this cipher which I know of, and is quite simple when you know of it. But few people could figure it out without having read it first. You can find a clear way of cracking it in The Code Book by Simon Singh (website is http://www.simonsingh.net/ ). There's also a harder-to-understand description of the method in Wikipedia.

And, to make encryption faster, there are devices called cipher discs. Here's a picture of one: http://home.ca.inter.net/~hagelin/HicksCipherDisk-1s.jpg and a cutout: http://www.secretcodebreaker.com/ciphrdk1.jpg . They're very easy to make. Just join a disc with the alphabet around it to a slightly larger disc with an alphabet around it with a pin through the middle, so as to have them rotate. Color the letter A in the outside disc. Let the outer disc be the plain text disc (representing unencrypted letters) and the inner one represent encrypted ones. This is how to use it: align the letter in the keyword (inner disc) to the outer letter A. Then search for the plain text letter in the outside disc and the letter it's aligned to on the inside disc (the encrypted letter, which is the one you want to write down). Repeat as you would with the usual Vigenere Cipher.

Answer 2

I didn't see the movie you mention, but single messages in the Playfair cipher (described on the first web page below) are almost unbreakable without knowing the keyword or key phrase used. Even if everyone knew that you were using Playfair, it wouldn't help them a bit (and that's Kerckhoffs' Principle - listed as number 2 of the 6 items on the second web page below).



However, there are methods to break Playfair when a lot of text is all encrypted with the same key, it, so use a fresh keyword for each page in your journal. And, of course, destroy each 5 x 5 encryption square immediately after using it.

Answer 3

I don't think you can give him credit for Cena per se, but the rest I do agree with. I'd also throw Mankind on the list. When it comes to The Rock and Stone Cold, I think Vince capitalized more on them than he actually did create their gimmicks. Stone Cold was doing the anti-corporate thing in ECW and the Rock was essentially just Dwayne Johnson finally snapping on the crowd after getting negative face reaction. I'd also put the character of Mr. McMahon on the list. I know it sounds strange, but Vince's greatest creation is probably his on-air persona.

Answer 4

im not sure about the Prestige, but i have heard of a rather brilliant way to incript messages. It's a 2 part method. the first part has to do with how you write the message. you use a combination of manuscript letters and cursive letters. the second part is developing a a code where different combinations of manuscript and cursive equal a letter; such as MCMM=K