We are in the era of ubiquitous computing in which the use and development of Radio Frequency Iden-
tification (RFID) is becoming more widespread. RFID systems have three main components: readers,
tags, and database. An RFID tag is composed of a small microchip, limited logical functionality, and an
antenna. Most common tags are passive and harvest energy from a nearby RFID reader. This energy is
used both to energize the chip and send the answer back to the reader request. The tag provides a unique
identifier (or an anonymized version of that), which allows the unequivocal identification of the tag
holder (i.e. person, animal, or items).
