pinentry-curses

About pinentry-curses

From Debian's package description

This package contains a program that allows for secure entry of PINs or pass phrases. That means it tries to take care that the entered information is not swapped to disk or temporarily stored anywhere. This functionality is particularly useful for entering pass phrases when using encryption software such as GnuPG or e-mail clients using the same. It uses an open protocol and is therefore not tied to particular software.

The program contained in this package implements a PIN entry dialog using the curses tool kit, meaning that it is useful for users working in text mode without the X Window System. There are sibling packages that implement PIN entry dialogs that use an X tool kit. If you install any of the graphical packages then this package is not necessary because the sibling packages automatically fall back to text mode if X is not active.

From Debian's description of the pinentry-curses package, under that package's license.