Form to Encrypt/Decrypt using Vigenere-style Cryptography

This particular form strips out all the characters that are not lowercase alphabet letters, encrypts them, and writes the result in a single block of text, so as to spoil information about word-length. It also shows you what it encrypted by changing the text on the left.


  1. Put in your password (codeword).
  2. Put in your plaintext.
  3. Click the "encrypt" button. The ciphertext appears. You can then email that to someone, if you want to.
  4. Delete the plaintext. Clicking the "decrypt" button restores it from the ciphertext. If someone emailed you some ciphertext, you could decrypt it in the same way.

plaintext ciphertext