NFC Key Fob: What It Is & How One Works

There are many options for contactless entry, and one of the most convenient is an NFC key fob. Just why are these gadgets so great? It has to do with being touchless, but also being small, incognito, and having a small transmission range. Ordinarily, a short range is not a bonus, but when it comes to access control, it is a helpful safety feature.

Why? Let’s dive in.

NFC Keyfobs

Near Field Communication Basics

NFC stands for “Near Field Communication,” which refers directly to the size of the transmission range of the device.

The core of any NFC device (or any RFID device, for that matter) is a small metal coil. When this coil comes inside the scope of the magnetic field generated by a reader device, the magnetism prompts the coil inside the device to generate an electric current. This initial contact is called “the handshake.”

Once the handshake is made and the reader and the NFC key fob are in contact, a tiny chip connected to the coil inside the key fob can transmit a data package to the chip in the reader. This data package lets the reader know the identity, so to speak, of the NFC access control card: an authorized person that is allowed past the lock. This is how NFC fobs and cards can serve as keys for electric locks, and also how usage information is collected.

This whole process is really fast–less than a second. 

NFC and Smartphones

All Apple and Samsung smartphones also have NFC capabilities. These devices can be used as an NFC key and as an NFC reader, usually with the help of an app to supply the necessary software.

We’re not going to cover just how that works here, since this article has a different focus, but if you want to know more about using smartphones as key cards you can check out another one of our blogs on this very topic. Read the “Bluetooth Reader Access Control” article here.


NFC Key Fob Uses

NFC devices all have that tiny chip inside that stores data. This means that you can program different key fobs to different levels of clearance.

This chip and the data it contains can be used in multiple ways that can be very useful in offices, manufacturing facilities, and multi-tenant situations. 

These uses all have to do with access control, but involve the customization of access control for maximum security.

For example:

  • Fob A can go through all exterior doors in the building
  • Fob B can go through all exterior doors and interior doors to sensitive areas like server rooms or data storage spaces
  • Fob C can go through exterior doors and into restricted-access equipment cages, but not the server room.

These key fobs can also be used as credentials for unlocking computers or even certain pieces of computer-operated equipment. Using NFC fobs for this is a way of limited access not just to areas, but to devices, ensuring that people who are not properly trained are simply unable to fire up and use whatever equipment they want.

Also read: Commercial Key Fob Door Lock System

key fob

Can NFC Key Cards Get Hacked?

Anything that uses radio communication, including Bluetooth, RFID, Wi-Fi, and NFC, can potentially be hacked.

However, there are things you (and your security team) can do to make them far more difficult to crack.

NFC key fobs in general are harder for hackers to gain access to because they are usually kept on an employee’s person when out in public, as opposed to in a bag that is more exposed.

Also, because NFC uses very short range near field communication, it is not as good of a candidate for cloning as, say, a longer-range RFID card, because a hacker would need to get very close to the card in order to scan and copy it.

(Wondering how the cloning thing works? We have another article on that here: Everything You Need To Know About Key Fob Cloning)

Additionally, new NFC key fobs and cards incorporate encryption to protect the information being exchanged. This means that the data on an NFC card is encoded using an encryption that is known to its assigned reader, but not to a potential hacker’s reader. The hacker can activate a handshake with an encrypted NFC key fob, but it cannot decode the data package, thus thwarting its efforts to clone the data and make a duplicate key.

For companies that like the ability to track access using NFC key fob credentials but are still concerned about security issues, consider two-factor authentication.

This means using two different credentials to approve access to a locked door. This could be a NFC key fob plus a PIN number, or an NFC fob plus a biometric fingerprint lock. This ensures that even if the near field communication is cracked, the hacker is still missing a second component that is crucial to opening a lock.

RFID cloning digital pickpocketing

Is NFC Better Than RFID?

RFID, or radio frequency identification, is very widespread in the security industry. RFID antedates NFC and is often less expensive to implement. But does that mean it is better?

NFC key fobs are smaller and, with the right encryption, can be more secure. Their data chip is also capable of carrying a lot more data (which is part of why they are so handy in smartphones). Their smaller transmission field makes them much more secure by default than longer-range RFID cards.

But RFID cards are well-suited for settings where the card and the reader need to be spaced more widely apart, and they are more affordable for security on a budget. More and more RFID cards are being deployed with built-in encryption that makes them more secure, as well.

RFID tends to be better for retail and general office settings where corporate sabotage is not a major risk factor. NFC tends to be better for manufacturing facilities or a business dealing in sensitive information, or business of that type, thanks to their more secure design and smaller profile.

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