Letter Numbers - Replace each letter with the number of its position in the alphabet.Gronsfeld - This operates very similar to a Vigenère cipher, but uses numbers instead of a key word.Double Columnar Transposition - Because two is better than one.A simple cypher, but one that is featured on the Kryptos sculpture at the CIA headquarters. Columnar Transposition - Write a message as a long column and then swap around the columns.Traditionally, the offset is 3, making A into D, B into E, etc. Caesar - A Caesar cipher lets you add an arbitrary value, shifting each letter forwards or backwards.An easy and fairly secure pencil & paper cipher. Bifid - Breaks information for each letter up and spreads it out in the encoded message.Base64 - This is typically used to make binary data safe to transport as strictly text.Baconian - Used to hide a message within another message by using different typefaces or other distinguishing characteristics.Atbash - A very simplistic cipher where you change A to Z, B to Y, and so on.Affine - Similar to a Caesarian shift, but also adds in a multiplier to further scramble letters.If you know of another cipher that you think should be on here or a tool that would be useful, request it and perhaps it can be added to the site. This is a page dedicated to simple text manipulation tools, which all can be replicated with just paper and pencil. If the message isn't that important or if it is intended to be decrypted by hand, you should use a simpler tool. You can use a full-blown encryption tool, such as PGP. Let's say that you need to send your friend a message, but you don't want another person to know what it is.

Vigenere cipher decryption tool