What is RFID and NFC Access Control?
In the context of door access control, radio frequency identification, or RFID, technology is used to enable the exchange of data between key cards and readers. Ideal for use in access control systems, RFID cards have a uniquely identifiable tag that can be detected by a reader up to a few feet away.
Near field communication, or NFC, technology is very similar to RFID, albeit more modern. While the functionality is similar, NFC is more typically found in mobile access control systems, in which smart tags activated on smartphones can act as both receivers and transmitters of data. A key difference is the more limited range of NFC technology (a few inches as opposed to a few feet).
RFID Door Access Systems
Most people have used an RFID door access system at one time or another. This combination of card reader and encoded key cards is common in places like hotels, businesses campuses, office buildings, and hospitals. At the core of this access control system is the embedded credential in each card, which can be read using RFID (radio frequency).
Advantages of RFID Door Access Systems
- Weather and waterproof: Assuming electricity is still running to the door, RFID door access systems will remain operational during weather conditions or water. Since there is no exposed card slot, RFID locks are generally waterproof.
- Customizable user permissions: Maintaining access security across multiple buildings, for a high volume of people, requires the ability to assign user permissions to particular groups. RFID cards can be programmed and reprogrammed as the aspects of security requirements change. If an employee leaves, the card can be deactivated quickly or reprogrammed for a new employee. It also allows changes to areas that personnel can access as their permissions expand or change.
- Durable to wear-and-tear: Durability might seem like an insignificant part of door access security, but most people have experienced the deterioration or malfunction barcode or magnetic strip technology. RFID chips are able to handle much more of a beating when compared to these technologies, which means employees and access admins can spend less resources replacing and reprogramming damaged or destroyed cards.
- Versatility: Thanks to the technology that powers them, RFID locks allow for more flexible door access control than traditional door lock systems. Homeowners, for instance, can better regulate access to different rooms, spaces, or safes within their home by configuring different cards or fobs to open different locks. The same principle applies for businesses and large enterprises.
Disadvantages of RFID Door Access Systems
- LF RFID vulnerabilities: RFID systems operate at different frequencies. Low-frequency RFID (LF RFID) cards create a signal that has the potential to be hacked. And even though, generally speaking, RFID readers have limited range, hackers and bad actors can get around this obstacle using signal boosters.
- Prone to electromagnetic interference: RFID cards are also prone to electromagnetic interference, which can come from other RFID cards, or any other magnetized device nearby. Electromagnetic interference can be used to jam cards and readers, preventing the cards from successfully transmitting information. This can be both a security risk and a resource drain over time.
- Key card copying: RFID cards are easily cloned by someone with the ability to pick up and read signals broadcast from card to reader. This information can be used to create a new card using a transponder.
- Malfunction during outages: Though RFID systems are generally durable through adverse weather conditions and water, power outages that disable the door system can present a problem if no electricity backup is available.
Security Features to Look For in an RFID Door Access System
While generally more secure than most legacy door access security solutions, RFID door access systems are not free of vulnerabilities. No system is. To ensure the highest level of security, here are the most important security features to look for when evaluating an RFID door access system:
- Mutual authentication: Look for systems with the built-in capability for smart cards to 1) verify that a reader is authentic; and 2) present authentication to the reader before starting a secure transaction (Apple Pay is a common example). Look for contactless smart devices (readers) that are able to verify the authority of a person based on a personal identification number (PIN), password, or biometric, to counter unauthorized access.
- Strong information security: This is especially important for applications requiring complete data protection. Look for solutions in which communication between contactless smart card-based devices and readers can be encrypted to prevent eavesdropping. In addition, hashes and/or digital signatures can be used to ensure data integrity, while random number generators can be used to enable dynamic cryptographic keys that prevent so-called “replay” attacks.
- Strong contactless device security: Like contact smart cards, contactless smart card technology is extremely difficult to duplicate or forge and has built-in tamper-resistance. Smart card chips include a variety of hardware and software capabilities that detect and react to tampering attempts. This helps counter possible attacks. For example, most chips are manufactured with extra metal layers, sensors to detect thermal and UV light attacks, and additional software and hardware circuitry to thwart differential power analysis.
- Support for biometric authentication: For the highest degree of security and privacy, look for smart card technology that can be implemented in combination with biometric technology. Biometrics are measurable physical characteristics, or personal behavioral traits, that can be used to verify someone’s identity (fingerprint, facial recognition, voice, and so on).
- Strong support for information privacy: Unlike other technologies, smart card-based devices allow you to implement a personal firewall for individuals. These firewalls can be configured to only release required information. The ability to support authenticated and authorized information access, alongside strong contactless device and data security, make contactless smart cards excellent guardians of personal information and individual privacy.
NFC Door Entry Systems
Door access security systems using NFC enable more advanced, secure deployments than their RFID counterparts. As mentioned, NFC makes a physical key card unnecessary—in most applications, a smartphone acts as the authentication “token.” Point of sale systems that allow people to pay with Apple Pay or Google Wallet are good examples of this technology at use in the real world.
The same principle applies to NFC-based door systems.
Advantages of NFC Door Entry Systems
- No need for physical key cards: Because NFC technology enables smartphones to act as key cards, there is no need to issue separate key cards. This helps to reduce overhead and ease the administrative burden for IT professionals managing access control.
- A low-maintenance solution: Easily incorporate NFC into cloud-based access control systems at scale and on an ad hoc basis. Adding and removing users is easy, security vulnerabilities are minimal, and overall administration requires far fewer resources.
- Reduced risk of intrusion and key theft: Rather than simply needing a key card to gain access to secure facilities, thieves and malefactors would need a user’s smartphone. Actually, they’d need the smartphone, as well as the ability to access that smartphone, adding a couple of extra layers of security.
Disadvantages of NFC Door Entry Systems
Despite their arguably superior technology, NFC door entry systems do have a few disadvantages.
- Shorter range: RFID readers have a range of a few feet, while NFC devices are limited to a few inches. This can create some inefficiencies when deployed at scale.
- Limited availability: At least in the United States, NFC-enabled devices are less commonly available than RFID. This makes finding and deploying an NFC system a bit more complicated.
Features to Look For an NFC System
Beyond the aforementioned core functionality common to most NFC systems, look for remote or scheduled unlock capabilities. Sometimes, the ability to bypass NFC reader authentication and grant access for a high volume of people is far more efficient. A simple example would be special office events, such as hosting partners, clients, or customers for an end-of-year party.