A credit card–sized device (or sometimes smaller) that has a embedded computer chip. This chip not only provides storage functionality but also can run programs. Smart cards are used in a number of security-sensitive applications. One important application of Smart Cards is in wireless telecommunication, where Smart Cards are used as Subscriber Identification Modules (SIM).

Another use is the health insurance card now employed in several countries around the world. The patient card contains a patient’s health history and a record of previous prescriptions. In addition to this data, a number of security algorithms are implemented on the card so that only properly authorized parties—doctors and/or nurses—can access and alter this data when they successfully establish their identity and authentication through the usage of a health professional’s version of the card.