A portable authentication system includes a security module, that may be a smart card, SIM (Subscriber Identity Module), USB controller with a secure chip, or similar module capable of storing one or more credentials, and an interface module such as a digital badge holder that is able to communicate with the security module, for instance by providing a smart card communication interface. The portable authentication system may be either a single integrated system or a dual system where the security module can be removed or disconnected from the interface system.