Vigenère Cipher Encoder/Decoder

This tool allows you to encode or decode text using the Vigenère Cipher, a method used for secure communication. It's suitable for students, educators, and cryptography enthusiasts.

Vigenère Cipher Calculator

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Data Source and Methodology

All calculations are based on the principles of the Vigenère Cipher, a well-documented cryptographic method.

The Formula Explained

The Vigenère Cipher uses a simple form of polyalphabetic substitution. Each letter in the text is shifted along the alphabet by a number of positions determined by a corresponding letter in the repeating key.

Glossary of Terms

How It Works: A Step-by-Step Example

Consider encoding the word "HELLO" with the key "KEY". The first letter, H, is shifted by the position of K in the alphabet, and so forth.

Frequently Asked Questions (FAQ)

What is the Vigenère Cipher?

A method of encrypting alphabetic text by using a simple form of polyalphabetic substitution.

How do I choose a key?

The key can be any word or phrase. The longer and more random the key, the more secure the cipher.

Can the Vigenère Cipher be cracked?

Yes, especially with short keys. Longer keys improve security.

Is this tool secure?

This tool is for educational purposes. Do not use it for sensitive information.

Why isn't the cipher working?

Ensure that the key and text are correctly entered, and that the mode is set appropriately.

Tool developed by Ugo Candido. Content verified by cryptography experts.
Last reviewed for accuracy on: October 1, 2023.