Security in RFID technology

Contactless communication technologies are increasingly used in both consumer and professional electronics. In today's article, we pay special attention to security in RFID technology and the principle of radio tags.

Radio-frequency identification, or RFID, technology makes it possible to identify objects using radio proximity communication. It is particularly associated with passive tags, which do not require additional power for operation. Their essence is a special design - tags are powered by inducing the flow of current due to the phenomenon of electromagnetic induction. They are used in industry, logistics and transportation.

The simplicity of implementation and high security of RFID open new opportunities for designers and engineers to apply the technology in industrial applications. An interesting example is the implementation of a machine identification system in a mine. This allows more efficient estimation of extraction and planning of work. Such a solution has been applied in one of the Scandinavian mines, where the system uses active tags.

What is RFID technology based on?

In the introduction we briefly answered the question - what is RFID technology about? In the following section we will discuss the essence of its operation in a bit more detail.

Most users may associate proximity data tags with transponders used to open doors in the form of cards and key rings. Components in this category usually operate at frequencies of either 125 kHz (Unique standard) or 13.56 MHz (MIFARE standard). However, it is worth mentioning that there are 3 groups of RFID frequencies.

It is worth mentioning that active UHF RFID tags can offer much longer ranges. However, they require an external power supply unlike passive tags. RFID transponders themselves are built from several components, i.e. an integrated circuit with a microprocessor and memory, a transmit/receive antenna and a housing.

An interesting aspect is the variety of memories used in the integrated circuit of a secure RFID card or any type of proximity tag. We distinguish between EPC memory, User Memory, TID memory and so-called security memory. The latter memory is a bank storing two 32-bit passwords, protecting the data stored in the RFID tag.

Security in RFID technology

A topic discussed by many engineers and decision-makers in the industry is security in RFID technology. Of course, one should be aware that in theory it is possible for example, to clone RFID cards. In practice, however, everything depends on the details of the proximity technology used. Manufacturers are developing more and more perfect solutions that clearly improve the security level of radio tags.

One of the problems that designers may run into is the possibility of interfering with the electromagnetic spectrum in which RFID technology operates. An example would be for example, the intentional excitation of active tags at high frequency. If the active tag is battery-powered, this causes the cell to wear out faster. As a result, the attacker can cause the power supply to shut down and consequently render the system inoperable.

Engineers may also run into problems recognising an impersonating tag as an unauthorised RFID transponder. One solution is to include a special recognition number - the digital signature of the RFID tag. Of course, this may raise some difficulties. If it becomes necessary to update the contents of the memory, user access to the security-sensitive system will be necessary.

Designers of RFID radio systems are constantly improving the transponders available on the market. The fruit of their work is a special Smart Mode. It allows tags to be recognised independently of EPC and TID numbers. Thus, even copying a card or tag with unique numbers will not allow a forged transponder to be used in the system. As a result, an RFID tag copied by an intruder will remain useless.

What blocks the RFID signal?

Blocking the RFID signal is one effective method of protecting against proximity card cloning. Specialised blockers, either in the form of a case or tag housing are made of diamagnetic materials, which have very low magnetic conductivity. As a result, they block the flow of electromagnetic fields, preventing accidental excitation of the transponder by an intruder wishing to copy the RFID tag.

How to destroy an RFID chip?

The simplest method to destroy an RFID chip is to mechanically damage either the chip or the antenna. This can be done by physically drilling into the transponder in the appropriate location. A more sophisticated method can be the emission of a directed stream of high-power microwaves. In practice, destruction of an RFID chip by an intruder is very difficult due to the level of complexity of the operation.

RFID security in industry

We already know that the security of RFID applications in industry stands at a high level. Proximity identification systems with the use of radio waves are getting better and better. The technology itself is used in access control systems, tool marking or cargo identification on warehouse floors. Due to the increasing level of RFID security, it is worth considering their implementation in an industrial plant.

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