ROT13 decoder noob question

[+One-O-7]

I am trying to figure this out. If I understand correctly, an A = N, B = O, C = P and vice versa, is this correct?

 

So if one writes NCCYR, it means APPLE! Is this correct? and PNG = CAT...

 

If that is so, then I understand, but there must be more to it than that because I am trying to solve a mystery puzzle in German and when I do the letter substitution, the resulting "words" cannot be understood by a German friend. He, of course, is fluent in German.

 

What am I missing?

 

Decryption Key

 

A|B|C|D|E|F|G|H|I|J|K|L|M

-------------------------

N|O|P|Q|R|S|T|U|V|W|X|Y|Z

 

(letter above equals below, and vice versa)

[jholly]

perhaps the mystery uses something other than a shift 13 for the Caesar cypher.

[+kunarion]

I am trying to solve a mystery puzzle in German

 

The "decryption key" applies to the hint (if any), not necessarily to any given puzzle. A mystery cache's "puzzle" could be practically anything. Look at the cache page's "Difficulty" rating. If it's a 2 or less, it's not considered too tough. Also read the cache logs, to ensure that people are easily solving it.

 

If you're generally good at solving word puzzles in German, it may simply be a matter of reviewing all info, and trying another idea. If you're stumped, ask the cache owner.

Edited August 20, 2014 by kunarion

[+Harry Dolphin]

True. I have one that uses ROT 1 (or is it ROT 23?) Hee hee hee.

[+cerberus1]

Drat! I thought you were gonna give another one away.

[+NYPaddleCacher]

True. I have one that uses ROT 1 (or is it ROT 23?) Hee hee hee.

 

Just as a generic puzzle solving technique, understand that a ROT13 (or ROT13) is just a shift cipher also called a caeser cipher. I Caeser cipher is a type of substitution cipher, which generally uses the English alphabet for both the encoded and decoded text. Each unique letter in the encoded text can be substituted with a distinct letter for the decoded text. However, if one considers each letter in the encoded text as a symbol, it doesn't really matter if the English alphabet is used. It works the same if, for example, the German alphabet was used, or Russian Cyrilic, Chinese symbols or even pictures.

 

If you identify each unique letter (or symbol) in the encoded text, write them down in a column, you can then write A, B, C...Z next to each symbol. Then you can use letter frequency analysis to identify the most common letters and assign them to E, T, A, O, I, N (there are several sites which list the most commonly used letters in the English alphabet). If you start with the most common letters the rest will come quickly as you identify words, especially if all the words are numbers. Once you've identified the substitute letter for E, T, and N is should be really easy to identify the substitutions for O, R, H, I, etc. and complete the code.

 

[+chrisandjanet]

I did one once where each word in the description was a different ROT - ROT 4 for the first word, ROT 6 for the second, etc. I spent a lot of time with graph paper manually decoding that one. Then it took another couple of hours to dawn on me that the decoded description wasn't the clue to find it, the ROT numbers were the actual cords.

 

Brute force is my go-to for puzzles, but sometimes you have to stare at it and wait for a flash of inspriation.