The term Radio Frequency Identification (RFID) refers to a technology that leverages radio waves to automatically identify and track tags attached to objects. An RFID system has two parts – tags and RFID reader. Tags are nothing but electronic chips containing digitized information. These tags can be of two types – passive and active. While the passive chips draw the necessary power from a nearby RFID reader’s radio waves, their active counterparts don’t have such limitations. They can source power from any external point such as battery and can track objects from a considerable distance. And it’s precisely this feature that hackers take advantage of. Think of your RFID-enabled card – all that an electronic pickpocket needs to do is come within a few feet of the card in a crowded place. That’s enough to extract information from the radio waves coming from your RFID chip cards with the help of simple electronic equipment. This possibility of automatic extraction of people’s personal information has raised serious privacy concerns, triggering the need for the development of RFID shielding solutions that help block the unintended signals.
Compliance Requirements for RFID Shields
Against the backdrop of rising RFID-induced crimes, the government has made standard specifications for shielding product development mandatory. Some of the standards that are used to address RFID issues include ISO/IEC 18000 and ISO/IEC 29167, on-chip cryptography methods for untraceability, tag and reader authentication, and over-the-air privacy, among others. RFID shielding products are also required to be compliant with the FIPS-201 guidelines. In addition, the federal government requires each new ID cards to be equipped with shielding sleeve or holder. But how do these protective solutions work? Let’s find out.
RFID Shields Mechanism
Let’s begin at the beginning. RFID is the name of the technology for the automatic identification of people or objects. Identification can be done in more ways than one. The most common among them is the method that involves storing serial numbers and other information that correspond to specific persons and objects on a microchip. Chips are connected to an antenna (chips + antenna=tag). The antenna is tuned to receive the electromagnetic waves sent out by the reader. An RFID tag (passive) comes to life by absorbing power from the electromagnetic field created by the reader. It then uses the power to activate a microchip’s circuits, modulate the waves, and send them back to the reader. The reader converts the new waves into digital data. The method uses a low level of power and leads to the creation of a narrow magnetic field. All these help the system to avoid getting encumbered by interfering signals. However, any nearby equipment that has a microchip and antenna-like structure such as power cord or cable can send out interfering and unwanted signals. Three shielding approaches are used to deal with this interference and keep the reader protected:
Strengthen the Reader
One of the best ways to bypass undesirable signals is making the reader strong enough so that it becomes less vulnerable to unwanted incoming signals. It is especially important to reduce the system’s sensitivity to the higher harmonics of lower frequency clock rates. There are two ways you can reduce the reader’s sensitivity to undesired signals – either move it closer to the tag source or tune the antenna for receiving information coming only from a particular direction.
Shield the Possible Sources
Move the reader further away from the potential sources to address the interrogation frequency. Alternatively, shield the neighboring equipment as far as possible to reduce interference.
Reduce RF Emissions
Keep the reader protected from scattered signals that the tags send back. This helps to free up the environment from unwanted interference signals and also bolster security.
Use RFID-specific frequency-tuned shielding solutions to control RFID signal interference. Shielding tools are available in many forms including signal interference probe, absorber shields, ferrite absorbers for cables and PCB shields. Choose an option that fits your application needs well.