qca: qca (Qt Cryptographic Architecture) qca: qca: QCA aims to provide a straightforward and cross-platform crypto API, qca: using Qt datatypes and conventions. QCA separates the API from the qca: implementation, using plugins known as Providers. The advantage of qca: this model is to allow applications to avoid linking to or explicitly qca: depending on any particular cryptographic library. This allows one qca: to easily change or upgrade crypto implementations without needing qca: to recompile the application. qca: qca: QCA was written by Justin Karneges.