Use your own PGP key
Note: To use the functions described in this article, you must have the mailbox Guard activated.
You can replace the PGP key pair automatically generated by Guard during setup with a self-created key pair. The requirement is that your current main mail address at mailbox is included in the user ID (UID) of the key.
Uploading a new key
Open the key management under All settings | mailbox Guard | Your keys.
Always upload your new key file first. Delete the automatically generated old key only after successfully uploading your new key pair.
To upload the self-created key pair, click in the key list on Upload private key. There you can select and upload your new key file.
Uploading only the public key
If you place particular importance on security, you can choose not to upload your private key to our server. In this case, upload only your public key.
Other Guard users can still send you encrypted mails. However, reading encrypted mails in the web client is not possible, since the private key is missing on the server. In this case, please use your local mail client with the corresponding PGP installation to decrypt encrypted messages.
Setting a new password
When you upload your key pair (private and public key), you will be asked to enter two passwords:
- The current password of your private key – this is required to access your private key after the upload.
- A new password for this key – this password should be identical to your current Guard password.
- The new password protects the private key in Guard.
- If you use a different password, you will no longer have access to your old keys and will not be able to delete them.
After successful upload, the new keys are automatically marked as Active. Existing older keys are marked as Inactive.
Maximum file size
Note: You can upload public keys with a maximum size of 65k. Keys that contain photos or many signatures can be larger and may cause error messages during upload.
To reduce the size of such keys, import them into your local key management (e.g., with GnuPG) and then export them again using the option --export-options export-minimal:
gpg2 --armor --export-options export-minimal --export <your-key-ID> > key4upload.asc
Deleting an old key
Warning: If you have already encrypted mails or data with an inactive old key, you will no longer be able to decrypt them once you delete this key. This also applies to your possibly enabled inbox encryption.
Inactive keys can be deleted via the three-stripes symbol in the key management. If the key is a private key, you will be prompted to enter your Guard password.
If you do not want to use a local installation of GnuPG, you must ask your communication partner to provide you with a minimal key.
