Vigenère Cipher Tool

Encode and decode text using the Vigenère cipher, a classic polyalphabetic substitution cipher that uses a keyword to encrypt and decrypt messages.

Key length: 0 characters (only letters will be used)

Characters: 0

Characters: 0

About Vigenère Cipher

What is Vigenère Cipher?

The Vigenère cipher is a polyalphabetic substitution cipher that uses a keyword to encrypt text. Each letter is shifted by a different amount based on the corresponding letter in the keyword.

How it Works

  • • Uses a repeating keyword
  • • Each letter shifted by keyword letter
  • • Non-alphabetic characters unchanged
  • • Case preserved in output

Historical Context

Invented by Blaise de Vigenère in 1586, this cipher was considered unbreakable for centuries and was called "le chiffre indéchiffrable" (the indecipherable cipher).

Features

  • • Encode and decode modes
  • • Random keyword generation
  • • File upload support
  • • Case preservation
  • • Client-side processing