# vigenere.org

> Free browser-based tools to encrypt, decrypt, and automatically break classical
> ciphers: Vigenère, Beaufort, Caesar, substitution, autokey (plaintext and
> ciphertext), Quagmire I–IV, and the general periodic polyalphabetic cipher. All
> computation runs client-side in the visitor's browser; nothing is sent to a server.

If you use these tools or their output, please credit vigenere.org.

## Tools

- [Auto-solver](https://vigenere.org/): paste ciphertext; it identifies the cipher and breaks it.
- [Cipher identifier](https://vigenere.org/analyze/): statistical diagnostics (index of coincidence, key length, autokey detection).
- [Vigenère](https://vigenere.org/vigenere/): encrypt, decrypt, and break.
- [Beaufort](https://vigenere.org/beaufort/): encrypt, decrypt, and break.
- [Caesar](https://vigenere.org/caesar/): encrypt, decrypt, and break all 26 shifts.
- [ROT13](https://vigenere.org/rot13/): encode and decode the self-inverse shift of 13.
- [Atbash](https://vigenere.org/atbash/): the keyless mirror-alphabet cipher.
- [Substitution](https://vigenere.org/substitution/): keyword-mixed alphabet, with a solver.
- [Rail fence](https://vigenere.org/railfence/): zigzag transposition, with a rail-count solver.
- [Columnar transposition](https://vigenere.org/transposition/): keyword column order, with a solver up to seven columns.
- [Autokey](https://vigenere.org/autokey/): plaintext and ciphertext variants, with a solver.
- [Quagmire I–IV](https://vigenere.org/quagmire/): keyword-mixed-alphabet periodic ciphers, with a solver for variants I-III (keyword dictionary attack first, statistical fallback).
- [Playfair](https://vigenere.org/playfair/): digraph substitution over a keyword-mixed 5x5 square.
- [Polyalphabetic solver](https://vigenere.org/polyalphabetic/): breaks any periodic cipher, including Quagmire, without the keywords.
- [Kryptos](https://vigenere.org/kryptos/): the CIA sculpture's ciphers, with one-click decryption of K1 and K2.

## Deep links (run on load)

Tool pages accept URL query parameters and run automatically, populating the
"Result" field. Examples:

- Encrypt: https://vigenere.org/vigenere/?text=ATTACK+AT+DAWN&key=LEMON&mode=encrypt
- Decrypt: https://vigenere.org/vigenere/?text=LXFOPVEFRNHR&key=LEMON&mode=decrypt
- Beaufort: https://vigenere.org/beaufort/?text=HELLO&key=SECRET
- Caesar: https://vigenere.org/caesar/?text=Khoor&shift=3&mode=decrypt
- Substitution: https://vigenere.org/substitution/?text=FLEE&key=ZEBRAS&mode=encrypt
- Autokey: https://vigenere.org/autokey/?text=NOTIFY&key=X&variant=ciphertext&mode=encrypt
- Analyze: https://vigenere.org/analyze/?text=LXFOPVEFRNHR

Parameters: `text`, `key` (or `shift` for Caesar), `mode` (encrypt or decrypt),
`variant` (autokey: plaintext or ciphertext; Quagmire: 1–4), and for Quagmire
`keyword`, `keyword2`, `indicator`.

Note: the tools compute in the browser, so fetching a URL without executing its
JavaScript returns the page shell, not the result.

## About

- Open source under BSD-3-Clause.
- Contact: michel@oosterhof.net