Playfair Cipher Tool

Encode and decode messages using the classic Playfair cipher. A free, secure tool that works directly in your browser.

Cipher Settings

Message

About Playfair Cipher

The Playfair cipher is a digraph substitution cipher, invented by Charles Wheatstone in 1854. It uses a 5×5 grid of letters to encrypt pairs of letters (digraphs) rather than single letters.

How it works:

  1. Create a 5×5 grid using a keyword (duplicates removed)
  2. Fill the rest of the grid with the remaining alphabet letters (I and J share a cell)
  3. Split the message into pairs of letters
  4. For each pair:
    • If both letters are in the same row, replace each with the letter to its right
    • If both letters are in the same column, replace each with the letter below it
    • Otherwise, replace each letter with the letter in the same row but in the other's column

Example:

With the keyword "PLAYFAIR", the message "HIDE THE GOLD" becomes "BM ND ZB XD KY BE".

How to use Playfair Cipher Tool

  1. Enter your keyword to generate the cipher grid.
  2. Type your message into the input text box.
  3. Select 'Encode' or 'Decode' to process your message.
  4. Copy your encoded or decoded result.

Features

  • Handles both encryption and decryption operations.
  • Automatically handles 'I' and 'J' as a single letter according to standard rules.
  • Processes messages of any length quickly and securely.
  • Creates a unique cipher square from your chosen keyword for personalized encryption.

Who Is This Tool For?

Ideal for students learning classical cryptography, hobbyists creating puzzle games, or anyone needing a simple method for encoding private messages.

Why Use Playfair Cipher Encryption?

The Playfair cipher provides a classic, digraphic encryption method that is more secure than simple substitution ciphers, perfect for educational purposes, basic data obfuscation, and creating engaging cryptographic puzzles.

Frequently Asked Questions

Is this Playfair cipher tool free?

Are my messages stored or shared?

How do I encode a message with the Playfair cipher?

Can I decode a Playfair cipher message?

What are the limitations for the keyword or message?

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