Ok, I admit that I don't know of an "official" name for this algorithm. I did hear that it is the same method as what a scytale (pronounced
ˈsitᵊl(ˌ)ē, like "Sit-a lee") employs. Basically, if you are given the encrypted text, you start at a given letter and then count N letters (wrapping around from the end to the beginning) forward to the next letter. It can be used for the third part of the Kryptos sculpture.
If you do use this for decoding Kryptos, you will see that you need to just count every 192nd letter. The "y", "a", and "r" are the three letters that are offset from the rest of the text. Also, the question mark at the end needs to count as a letter, so I changed it to "z". The first example encodes with a skip of 191 (to get every 192nd letter) and the second example decodes using a skip of 250 - the same result, showing that this algorithm can be used to encode and decode similarly.
This page will only move letters around by default. That's because moving spaces can cause some problems, especially for decryption. If you want to live dangerously, feel free to enable the option. If you want to know more about the type of problems it causes, check out the example.
- - This uses the "encode" mode to decode the message.
- - Shown as a decrypt example
- - Try to copy the encoded text and decode it. If you don't copy the spaces very carefully, the message won't be decoded properly.