Beaufort Cipher
Encrypt and decrypt with the Beaufort cipher — a self-reciprocal polyalphabetic cipher where the same key and operation both encrypts and decrypts.
What Does This Tool Do?
The Beaufort cipher is a polyalphabetic substitution similar to Vigenere but using the formula E = (key − plaintext) mod 26 instead of addition. It is self-reciprocal — the same keyword and operation both encrypts and decrypts.
Key Features
Self-Reciprocal
Same key and click encrypts AND decrypts.
Keyword-Based
Any alphabetic keyword.
Preserves Case
Case of original text maintained.
Copy Result
One-click copy.
How to Use
- Enter your text.
- Enter a keyword.
- Click Encrypt / Decrypt — the same button does both.
Frequently Asked Questions
How does Beaufort differ from Vigenere?▾
Vigenere: E = (plain + key) mod 26. Beaufort: E = (key − plain + 26) mod 26. This makes Beaufort self-reciprocal — decrypting uses the exact same steps.
What does self-reciprocal mean?▾
Applying the same operation twice returns the original text. E.g. encrypt "HELLO" with key "BEAUFORT" → get ciphertext → apply same operation again → get "HELLO" back.
Is Beaufort more secure than Vigenere?▾
They have the same security level — both are broken by Kasiski/index-of-coincidence analysis. Beaufort's advantage is purely operational convenience.
Complete Guide to Beaufort Cipher
When To Use This Tool
Use Beaufort Cipher whenever you need fast, accurate output without installing software. This tool is designed for speed, clarity, and repeatable results for day-to-day work.
Best Practices for Accurate Results
- Double-check the format of your input before running the tool.
- Test with a small sample first, then process larger data.
- Use Related Tools to verify, convert, or transform the output.
Why Users Prefer AdeDX
AdeDX tools are browser-based, free to use, and built to work across desktop and mobile devices. Most processing happens directly in your browser for fast performance and improved privacy.