An Introduction to RFID: What is a Smart Card?

I chose to introduce this newsletter concerning RFID with a "conceptualized metaphor" that encapsulates RFID technology within day-to-day applications (e.g. IDs, passports, credit cards, and e-tickets); to detail RFID in the context of smart cards. Here, we begin with the title of the article. What is smart card technology, and how does it apply to the world of RFID?

In short, smart cards are polymer debit-sized cards which have embedded processor technology (i.e. a smart chip), paired with other circuit peripherals, such as but not limited to storage capacity, cryptographic functionality, and I/O (i.e. input / output) channels. Here then, the primary characteristic which distinguishes a "smart card" from traditional magnetic stripe cards is that smart cards are not easily forged or copied. To detail, magnetic stripe cards are highly susceptible to fraud (e.g. "skimming" and counterfeiting). The reason why magnetic stripe cards can be easily penetration-tested is because of the method in which information is embedded onto the magnetic stripe of the given card.

Unseen to the human eye, information is stored onto the magnetic stripe of a magnetic stripe card. Wherein, the stripe is encoded with information by manipulating its magnetic dipoles using a "strong" magnetic field; the magnetic field controls the orientations of the dipoles along the stripe. Wherefore, the alignment (i.e. orientation) of those magnetic dipoles is preserved even when the polarizing magnetic field is removed from the stripe containing the dipoles storing the information; the orientation of the dipoles is its encoding and the superposition of the dipoles relative to their orientation-manipulated by the polarizing magnetic field is the information embedded within the stripe of the magnetic stripe card.

With this, not only can the information on the stripe be easily copied by reading the magnetic spatial gradient map of the stripe, but the storage capacity of magnetic stripe cards is poor. To be specific, how information is stored on a stripe is through the Wiegend format. To illustrate, multiple tracks are stored along the stripe of the magnetic stripe card, where each track on the stripe is embedded with a few bits of information; the superposition of the information of the aggregated tracks on the stripe provide the complete "domain of information." That being said, how does an EMV (i.e. electromagnetic voltage) solution, such as smart card technology (e.g. smart card, smart chip, etc.), compensate for the lack of security features which magnetic stripe cards retain? In short, the characteristics of smart card technology are that they have a unique identifier (e.g. a MAC address); can participate in automated electronic transactions; is primarily used to add security and is not easily forged or copied; can store data in a secure fashion; can accommodate cryptologic functionality. Wherefore, as a means to illustrate the internals of a smart card, it is best to evaluate the contacts of a chip card. Here, a contact is a "port of utility" for the smart chip; by ISO standard, there are 8 ports located on the smart chip. Where, the functions located on the ports of the chip house Vcc (i.e. input voltage), Gnd (i.e. grounding), RST (i.e. a reset clock), SWP (i.e. Near Field Communication Single-Wire Protocol), I/O (i.e. a communications input-output line), and a high-speed USB interface (i.e. USB+ and USB-, respectively).

Albeit a contact chip card is accessed by placing it within a card reader (or by using an RFID reader with NFC capability, assuming that the contact chip has an NFC-dongle as part of its integrated-package-peripherals) which makes physical contact with the metal pads that are located relative to the physical location of the contacts of the chip card, allowing for the chip to be powered, clocked, and for I/O communications to proceed. Wherein, the activation of the chip card when being plugged into RFID readers is facilitated by the physical property of electromagnetic induction.