Privacy friendly applications using citizen cards based on cryptographic smartcards

Citizen Cards are being deployed nowadays. Several applications are being developed using such cards. Different kind of services can be provided with such cards, from services demanded by the Administration, to applications from private companies. Unfortunately there is a great amount of applications that are not able nowadays to use the security these cards offer, due to their requirement of keeping the end-user anonymous. This requirement can be forced by the kind of application (e.g. restricted to certain ages), of by data protection laws, where there is no need to access personal data to provide a local service. Authors are proposing in this paper two solutions for this kind of services, benefiting from the already deployed citizen cards, reducing the cost of developing a new card, as well as maintain the card system.