GnuPG is a publicly available encryption scheme that uses the "public key" approach. With GnuPG, messages are encrypted using a public key; however, they can only be decrypted by a private key retained by the message's intended recipient.
How Do These Keys Work
You keep your private key secret from everyone, but you give your public key to anyone who wants it.
If you want to send someone an encrypted email, you need to get their public key and use that to perform the encryption. The receiver must use their private key to decrypt the email.
If you want someone to send you an encrypted email, you need to give them your public key. Once an email is sent to you, you must use your private key to read it.
Using the GnuPG keys is a very advanced task. Please refer to the following link for a user guide:
How To Create a New GnuPG Key
To set up GnuPG Keys:
- Log in to cPanel.
- Navigate to the Email section, then click on the Encryption icon.
- Enter the necessary details.
- In the Your Name field, enter the name you want to be seen during secure communications.
- In the Your Email field, enter the full email address you will use with the pair of keys.
- In the Comment/Nickname field, enter a short reminder about the purpose of this key pair.
- In the Key Password field, enter the password you desire for the encryption. Be sure to enter the same password again on the following line to confirm.
- In the Expiration Date, enter a value in years or weeks or days, but not a combination of those. So, if you need 1 year and 3 weeks, enter "55w." If you need 1 year, 3 weeks, and 2 days, enter "388d."
- In the Key Size dropdown, select the size of the encryption key. A bigger number means better encryption.
- Click the Generate Key button, and you will be able to view both keys.
How to Import an Existing GnuPG Key
You can also import an existing key by following the steps listed below:
- At the bottom part of the Encryption page in cPanel, click the Import Public GPG Key button.
- Copy the key code you want, and paste it into the text area provided.
- Click the Import button.
The key will then be added to your account.
For instructions on how to install encryption keys, please the documentation below from popular email clients: