pinentryqt4

pinentryqt4 is the Qt4-based graphical frontend of the pinentry program used by GnuPG and related tools to securely collect passphrases and PINs from the user. It provides a small graphical dialog and communicates with gpg-agent using the standard pinentry protocol.

When a private key operation or a smartcard PIN is required, GnuPG invokes pinentryqt4 to prompt the user. The program runs as a separate process, displays a modal window, and returns the entered secret to the calling process through the pinentry protocol, without exposing it to the terminal.

It is packaged under the pinentry-qt4 name in many distributions and can be configured via pinentry.conf to customize the window title, prompt text, and certain behavior. It works with X11 environments and is part of the family of pinentry frontends such as pinentry-gtk2 and pinentry-qt5.

Because Qt4 has been superseded by newer Qt versions, pinentryqt4 is considered legacy on many systems. Some distributions have deprecated or removed it in favor of pinentry-qt5 or pinentry-qt6, and compatibility with modern environments may vary.

See also: pinentry, GnuPG, gpg-agent, pinentry-qt5.