Smart Cities aim at improving the daily life of the citizens, by upgrading the services in terms of mobility, communications and power efficiency. Also, by measuring and acquiring the habits of a specific subject, it is meant to offer specific user-oriented services. In this scenario, biometric recognition covers a privileged role. Researchers worldwide agree with the fact that biometric credentials are difficult to be stolen and do not need to be remembered, so making them suitable for on-the-move authentication or video surveillance applications in smart cities environments.