RFID tags are useful for a huge variety of applications. Some of these applications include: supply chain management, automated payment, physical access control, counterfeit prevention, airline baggage management, and smart homes and offices. RFID tags are also implanted in all kinds of personal and consumer goods, for example, passports, partially assembled cars, frozen dinners, ski-lift passes, clothing, EZ-Pass toll collection devices, and public transportation tickets. Implantable RFID tags for animals allow concerned owners to label their pets and livestock. Verichip Corp. has also created a slightly adapted implantable RFID chip, the size of a grain of rice, for use in humans. Since its introduction, the Verichip was approved by the U.S. Food and Drug Administration, and this tiny chip is currently deployed in both commercial and medical systems. A great deal of information is available on RFID technology. Some introductory Web pages are listed here .

Radio Frequency Identification (RFID) is the latest phase in the decades-old trend of the miniaturization of computers. RFID transponders are tiny resource-limited computers that do not have a battery that needs periodic replacement. RFID tags are inductively powered by their external reading devices, called RFID readers. Once the RFID tag is activated, the tag decodes the incoming query and produces an appropriate response by using the energy of the incoming radio wave to power the chip long enough to respond. RFID tags can do a limited amount of processing, and have a small amount (<1024 bits) of storage.