Caesar Cipher
Encrypt/decrypt with the Caesar shift cipher — any shift 1-25, ROT13 preset, brute-force solver showing all 25 candidates, and frequency-analysis auto-crack. 100% private.
About Caesar Cipher
Encrypt/decrypt with the Caesar shift cipher — any shift 1-25, ROT13 preset, brute-force solver showing all 25 candidates, and frequency-analysis auto-crack. 100% private. Everything runs locally in your browser — your data never leaves your device.
How to use
- Enter your input in the tool above.
- Adjust any options to your preference.
- Use the Copy or Download buttons to save the result.
- Everything happens locally — your data never leaves your browser.
FAQ
Is the Caesar cipher secure?
No. The Caesar cipher is a classical cipher from antiquity — it has only 25 possible keys and is trivially broken by frequency analysis. Never use it for real security. It's included here for education and puzzle-solving.
How does the brute-force solver work?
It tries all 25 possible shifts, computes a chi-squared statistic comparing the letter frequencies of each candidate plaintext to English, and ranks them. The lowest chi-squared score is the most likely correct decryption.
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