https://mailvelope.com

Mailvelope is a tool to send and receive encrypted messages and files to other users. It uses PGP public key cryptography with a default private key size of 4096 bytes.

Mailvelope is a browser add-on that you can use in:

• Chrome
• Edge
• Firefox
• Brave
• Other Chromium based browsers

Tutorial: https://mailvelope.com/en/help

Generate a public and private key pair first. Export both keys and move the file to your back up.