Near-Field Communication: It Pays: Mobile payment systems explained and explored.

The exchanging of goods for a recognized symbol of value called currency has occurred on our planet for tens of thousands of years. The concept has stayed the same: an object represents a set value that is exchanged for goods and services. The object is then reused for other goods and services, with the object\´s value set by the local or international level of a group of individuals, which sets the value through a complex set of value or trust factors. At one time, precious metals were used, like gold and silver, and then we progressed, first to paper money, specialized paper notes issued by a regulatory body; then checks, paper notes that reference a local bank; and credit cards, plastic cards with identifiers that represent banks or credit-issuing institutions as well as the individual borrower of the credit. The inherent problem still existed that if the paper money, checks, or credit card were lost, stolen, or copied, the individual would lose the value, or "net worth", of his or her economic buying power. Multiple ideas have been pursued to strengthen the security of exchanging these trust-based tokens of material wealth. An idea that has been explored since the late 1960s (roughly 1968) is the use of radio-frequency identification (RFID) technology.