Let's say that you need to send your friend a message, but you don't want another person to know what it is. You can use a full-blown encryption tool, such as PGP. If the message isn't that important or if it is intended to be decrypted by hand, you should use a simpler tool. This is a page dedicated to simple text manipulation tools, which all can be replicated with just paper and pencil. If you know of another cipher that you think should be on here, leave me a message below. Affine Similar to a Caesarian shift, but also adds in a multiplier to further scramble letters. Atbash A very simplistic cipher where you change A into Z, B into Y, and so on. Baconian Used to hide a message within another message, by using different typefaces or other distinguishing characteristics. Base64 This is typically used to make binary data safe to transport as strictly text. Bifid Breaks information for each letter up and spreads it out in the encoded message. An easy and fairly secure pencil & paper cipher. Caesarian Shift Where ROT13 was based on you adding 13 to the letters, a Caesar cipher lets you add an arbitrary value. Again, you can do it with the cryptogram solver, but you can scroll through values of N pretty easily with this tool. Keyed Caesar Similar to a Caesar cipher, but you first alter the encoded alphabet with a word or phrase. Columnar Transposition Write a message as a long column and then swap around the columns. Read the message going down the columns. A simple cypher, but one that is featured on the Kryptos sculpture at the CIA headquarters. Double Transposition Because two is better than one. Used by the U.S. Army during World War II. Cryptogram Solver This helps you solve simple ciphers; the methods where you replace letter X with letter Y. Gronsfeld The exact same thing as a Vigenere cipher, but it uses numbers instead of a key word. Morse Code Once used to transmit messages around the world, this system can still be used in certain situations to send messages effectively when alternate mediums are not available. Letter Numbers Replace each letter with the number of its position in the alphabet. A simple replacment method that is usually the first one taught to children and is still an effective way to obscure your message. One Time Pad A virtually uncrackable cipher that relies heavily upon a random source for an encryption key. Playfair This cipher uses pairs of letters and a 5x5 grid to encode a message. It is fairly strong for a pencil and paper style code. Railfence A mildly complicated one where you align letters on different rows and then squish the letters together in order to create your ciphertext. ROT13 A popular method of hiding text so that only people who actually take the time to decode it can actually read it. You swap letters; A becomes N, and N becomes A. It was quite popular on bulletin board systems and Usenet newsgroups. You can do it with the cryptogram solver also, if you make A=N, B=O, C=P, etc. Rotate This acts as though you are writing the letters in a rectangular grid and then rotating the grid to the left or right 90°. Skip To decode this, you count N characters, write down the letter, count forward N characters, write down the letter, etc. It is used for section 3 of the Kryptos. Substitution Substitute your plaintext letters with other letters, images, or codes. Includes two common pigpen ciphers and the Sherlock Holmes' Dancing Men cipher. Übchi A double columnar transposition cipher that uses the same key, but adds a number of pad characters. Used by the Germans in WWI. Vigenere A special cipher somewhat based on the Caesarian shift, but you change the value of N with each letter and it is all based on a passphrase. A pretty strong cipher for beginners, and one that can be done on paper easily. Keyed Vigenere This modified cipher uses an alphabet that is out of order. Two keys are used. One creates the alphabet, the second is the encoding passphrase. This was created to help decrypt the Kryptos sculpture. Vigenere Autokey Instead of repeating the password used in order to encrypt text, this uses the password once and then the plaintext. It is harder to break than if you were to just use the password to encrypt your message. Related Tools These pages are not cipher pages, but they do relate to ciphers. They are included here to make your life easier. Cryptogram Solver If you have a plain text message, this will help find possible solutions in a matter of seconds. It works with simple substitution ciphers in plain English only. Letter Frequency Shows how often certain letters appear in your text. Used primarily to assist in decryption. Text Manipulator Change text around, make things upper- or lowercase,count/remove spaces. Also does various statistical analyses on the source text.