Application Secure Key

GpgFrontend keeps one key of its own. This key locks the data the program saves for you: settings, cached details, key server entries, and so on.

This is not one of your OpenPGP keys. It never touches your messages, your files, or your keyring. GpgFrontend makes it for you the first time it runs, and you never have to think about it.

Most people can stop reading here. The rest of this page is for people who want more protection than the default.

Your Three Choices

Open Settings, go to Advanced, and look at Application Key Protection.

No extra protection

The default. The key sits in a file that only your user account can read.

This is fine for a computer only you use. Anyone who can read your files could also read the key, but someone with that much access could read most of your other things anyway.

System keychain

GpgFrontend stores its key in the place where your computer already keeps passwords:

Windows: Credential Manager
macOS: your login keychain
Linux: your password service, such as GNOME Keyring or KWallet

Nothing changes for you day to day. The program never asks you for anything. It just means the key file on its own is useless to someone who copies it.

This choice is greyed out when it cannot work:

On a portable copy, because the store belongs to one computer and a portable copy has to run on any of them.
On a profile you opened from a file, for the same reason. That file is already protected by its own passphrase.
On Linux, when no password service is set up. Install one and switch it on, then try again.

PIN at startup

You choose a PIN, and GpgFrontend asks for it every time it opens. Nothing it saved can be read until you type it.

This is the strongest of the three. It is also the only one where you can lose data.

Use Change PIN on the same settings page to pick a new one later. You need the current PIN to do it.

Secure Level

On the same settings page, just above the key protection choices, you will find Secure Level. It has four settings:

Standard: no extra hardening. The default.
Enhanced: wipes memory as soon as it is finished with it.
Strong: also keeps sensitive memory out of the swap file.
Maximum: also changes the program’s internal key every week.

The first three are about memory, and are explained on Memory Security.

Maximum is the only one that affects this page. It replaces the key with a new one every week. So if someone steals an old copy of your saved data, it soon becomes useless to them.

Changes on this page only take effect after GpgFrontend restarts. It offers to restart for you.

Where the Key Is Kept

The key lives inside the profile you are using, in a folder called secure. If you use several profiles, each has its own key, and each can have its own protection setting.

Good Habits

Back up your OpenPGP private keys and revocation certificates separately. This key is not a backup of anything.
If you pick a PIN, write it down and keep it somewhere safe.
If you want protection with nothing to remember, pick System keychain.