Vigenere cipher breaker
This online calculator tries to decode Vigenere cipher without knowing the key. It uses the index of coincidence technique.

This content is licensed under Creative Commons Attribution/Share-Alike License 3.0 (Unported). That means you may freely redistribute or modify this content under the same license conditions and must attribute the original author by placing a hyperlink from your site to this work https://planetcalc.com/7948/. Also, please do not modify any references to the original work (if any) contained in this content.
Articles that describe this calculator
Frequency of Letters
arrow_upwardarrow_downwardLetter | arrow_upwardarrow_downwardFrequency | ||
---|---|---|---|
Key
Decoded message
Decoded with guess key
The file is very large. Browser slowdown may occur during loading and creation.
URL copied to clipboard
Comments