In a simple (monoalphabetic) substitution cipher, the alphabet is rearranged so you consistently replace each letter in your message for another letter or symbol. For instance, every “A” might appear as “M,” every “B” as “Q,” and so on, maintaining the same letter-to-letter mapping across the entire puzzle. They are commonly used for puzzle-solving and recreational cryptograms. In this context, if the ciphered text retains the spacing between words, it is called an Aristocrat. If the spacing is removed, making it harder to distinguish word boundaries, it is referred to as a Patristocrat.
Note: You can use the tool below to solve monoalphabetic substitution ciphers. There are many other types of cryptograms. This Cipher Identifier Tool will help you identify and solve other types of cryptograms.
Substitution Cipher Solver Tool
Text
Key
Click on a letter and then type on your KEYBOARD to assign it.
Instructions
You can decode (decrypt) or encode (encrypt) your message with your key. If you don't have any key, you can try to auto solve (break) your cipher.
Settings
- Language: The language determines the letters and statistics used for decoding, encoding and auto solving.
- Iterations: The more iterations, the more time will be spent when auto solving a cipher.
- Max Results: This is the maximum number of results you will get from auto solving.
- Spacing Mode: This is about the spaces (word breaks) in the text. In most cases it should be set to Automatic. In case a specific letter (for instance X) is used as word separator, set it to Substitute.
Auto Solve Results
| Score | Text |
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Not seeing the correct result? Try changing the Auto Solve Options or use the Cipher Identifier Tool.
Letter Frequencies
| Letter | Count | Percent |
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Word finder
Results
Saved work
Substitution Cipher Features
- The most common substitution ciphers are simple (monoalphabetic) substitution ciphers, meaning it uses only one set of substitutions for the whole message.
- The American Cryptogram Association (ACA) uses the names Aristocrat (a cryptogram that includes separators between words) or Patristocrat (a cryptogram that doesn't separate words). In both cases, a letter is not allowed to be substituted by itself.
- Another common name for monoalphabeic substitution ciphers is cryptoquip.
- As opposed to monoalphabetic substitution ciphers, there are also polyalphabetic substitution ciphers, for example Vigenère or Beaufort, where letters are not consistently substituted but where the substitution follows a pattern instead.
- Substitution ciphers originally were intended for military or personal secrets. The first know usage for entertainment purposes occured during the Middle Ages.
- Instead of spaces, a letter like X can be used to separate words.
- Frequency analysis can be used to find the most commonly used letters.
- A Caesar Cipher is a special kind of monoalphabetic substitution cipher, in which each letter is simply shifted a number of positions in the alphabet. It can easily be solved with the Caesar Cipher Tool.
- A ROT13 Cipher is similar to a Caesar Cipher, but with a fixed shift of 13 letters. It can easily be solved with the ROT13 Tool.
Sample Substitution Cipher
Code-breaking is not only fun, but also a very good exercise for your brain and cognitive skills. Why not try your cipher solving skills on this sample crypto?
pg szpb jf vcecrig fzjv rib mjek zsv j zp mcjsm rc rib bpbezkv ujrg rc zft rib mebzr cy rc fbsv pb lzut rc tzsfzf
See also: Code-Breaking tools | Adfgvx cipher | Adfgx cipher | Affine cipher | Atbash cipher | Baconian cipher | Beaufort cipher | Bifid cipher | Caesar cipher | Columnar transposition | Cryptogram | Double transposition | Enigma machine | Four-square cipher | Gronsfeld cipher | Keyed caesar cipher | One-time pad | Pigpen cipher | Playfair cipher | Rail fence cipher | Rot13 | Route transposition | Trifid cipher | Variant beaufort cipher | Vigenere cipher