SLS Team Java Library
Open source fork of the Google Authenticator Android app
GMR digital signature system
FIDO strong authentication, encryption, digital signature engine
Open source version of Google Authenticator (except the Android app)
The Remarc Mobile-ID USAT applet
Java code for signing and handling Croatian fiscal service requests
Java code that enables you to sign documents using a smart card.
A simple example of polyalphabetic cipher in Java.