With OpenPGP Applet you can encrypt or sign text using the public key encryption of OpenPGP.

It is unsafe to write confidential text in a web browser since JavaScript attacks can access it from inside the browser. You should rather write your text in a separate application, encrypt it using OpenPGP Applet, and paste the encrypted text in your browser, before sending it by email for example.

When using OpenPGP Applet to encrypt emails, non-ASCII characters (for example non-Latin characters or characters with accents) might not display correctly to the recipients of the email.

If you are going to encrypt emails often, we recommend you to set up Thunderbird instead.

This technique requires you to use public-key cryptography. If you never used OpenPGP keys before, you might rather want to encrypt your text using a passphrase with OpenPGP passphrase encryption. See the corresponding documentation.

  1. Write your text in a text editor. Do not write it in the web browser!

    Click on OpenPGP Applet and choose Open Text Editor to open gedit.

  2. Select with the mouse the text that you want to encrypt or sign. To copy it into the clipboard, right-click (on Mac, click with two fingers) on the selected text and choose Copy from the menu.

    OpenPGP Applet now shows lines of text, meaning that the clipboard contains non-encrypted text:

  3. Click on OpenPGP Applet and select Sign/Encrypt Clipboard with Public Keys from the menu.

    If you receive the error message “The clipboard does not contain valid input data”, try to copy your text again, starting from step 2.

  4. If you want to encrypt the text, select one or more public keys for the recipients of the encrypted text in the Choose keys dialog box. To select a public key, double-click on the corresponding line in the Select recipients list box.

  5. If you want to sign the text, select the secret key with which you want to sign the text in the Sign message as drop-down list.

  6. If you want to hide the recipients of the encrypted text, select the Hide recipients check box. Otherwise anyone who sees the encrypted text can know who the recipients are.

  7. Click on the OK button.

    If you receive the warning message Do you trust these keys, answer it accordingly.

  8. If you selected one or several public keys to encrypt the text, OpenPGP Applet now shows a padlock, meaning that the clipboard contains encrypted text:

    If you only selected a secret key to sign the text, OpenPGP Applet now shows a seal, meaning that the clipboard contains signed text:

  9. To paste the encrypted or signed text into another application, right-click (on Mac, click with two fingers) in the application where you want to paste it and choose Paste from the menu.

    For example, you can paste it into the web browser to send it by email.

    Encrypted text starting with -----BEGIN PGP MESSAGE-----

To store your GnuPG keys and configuration across different working sessions, you can turn on the GnuPG feature of the Persistent Storage.