Caesar Cipher
Encrypt, decrypt, and brute-force Caesar cipher text with real-time output and adjustable shift values
Texte Brut
Ciphertext
Caesar Cipher
Encrypt, decrypt, and brute-force Caesar cipher text with real-time output and adjustable shift values
Fonctionnalités
- Encrypt / decrypt with a configurable shift (0–25)
- Shift 13 = ROT13 (the classic "rotate by half the alphabet" variant)
- Preserves case and passes through non-letters (digits, punctuation, whitespace) unchanged
- Decrypt mode uses (26 − shift) so the inverse is just a one-click toggle
- Runs entirely in your browser
Mode d'emploi
- Choose Encrypt ou Decrypt mode en utilisant le toggle buttons.
- Définir le shift valeur en utilisant le slider ou nombre entrée (0-25).
- Type ou collez votre texte dans le entrée area — le sortie updates dans real time.
- Utiliser le Brute Force bouton à see tous 26 possible decryptions.
- Cliquez Copy à copy le sortie ou tout brute-force résultat à votre presse-papiers.
Conseils et bonnes pratiques
- Caesar cipher is a teaching tool, not real cryptography — there are only 25 distinct shifts so brute-force is instant.
- ROT13 (shift 13) is self-inverse: applying it twice returns the original text. Useful for obscuring spoilers.
- Letter case is preserved: A→D, a→d at shift 3.
- Non-letter characters (numbers, punctuation, spaces) pass through without change.
- Runs entirely in your browser.
FAQ
What is a Caesar cipher?
A Caesar cipher is one of the oldest known encryption methods. It works by shifting each letter in the alphabet by a fixed number of positions. For example, with a shift of 3, A becomes D, B becomes E, and so on. It is named after Julius Caesar, who reportedly used it for military correspondence.
How does the shift value work?
The shift value determines how many positions each letter moves in the alphabet. A shift of 1 turns A into B, a shift of 13 turns A into N (this is ROT13), and a shift of 25 turns A into Z. A shift of 0 or 26 returns the original text.
What is the brute-force feature?
Since there are only 26 possible shifts (0-25), the brute-force feature shows the result of applying every possible shift to your input text. This is useful for cracking a Caesar cipher when you do not know the original shift value.
Is my data private?
Yes. All encryption and decryption happens entirely in your browser using JavaScript. No data is sent to any server or third party.
Can I use this for real security?
No. The Caesar cipher is a simple substitution cipher that can be broken trivially by brute force (only 26 keys). It is useful for learning about cryptography, puzzles, and CTF challenges, but not for protecting sensitive data.