qca-demo is a small Qt GUI wrapped around Qt Cryptographic Architecture’s OpenPGP support — enough to load keys and encrypt/decrypt through QCA rather than shelling out to gpg directly. It’s a demo, not a library: a CryptWin widget and a main.cpp, meant to be read more than depended on, for anyone else trying to figure out QCA’s PGP API from the examples that exist rather than the documentation.