Everything you need to know about iCLASS® cards

Everything you need to know about iCLASS® cards

by Mike Boehm on May 11, 2023

iCLASS® cards are a type of contactless smart card technology produced by HID Global. The cards utilize the 13.56 MHz frequency and are used in a variety of security and access control applications, including employee identification, building access, and cashless payment systems. Continue reading to learn everything you need to know about iCLASS® RFID cards.


First, A Word About HID Global

As mentioned, iCLASS® cards are manufactured by HID Global, which is a familiar name to anyone working within the security and access management sector. HID Global is a major leader in the creation of secure identity solutions. They operate in over 100 countries and serve millions of customers worldwide. 

The company's products are used in a variety of sectors, including government, education, healthcare, financial services, and transportation. HID Global provides a range of proprietary RFID or NFC cards:

  • iCLASS® Seos®
  • iCLASS® SE
  • iCLASS® (Classic)
  • Crescendo®
  • HID Proximity


In addition to these proprietary cards, HID products a range of other formats meant to rival major competitors, including Wiegand, MIFARE, DESFire, and Indala cards. They often partner with original equipment manufacturers (OEM) like Honeywell and Siemens to help these companies incorporate access management tools into their products.  


What is iCLASS®? 

iCLASS® represents a versatile line of high-frequency access cards. Here are some of the key features of iCLASS cards:


  • Contactless technology – iClass® cards use RFID (Radio Frequency Identification) technology for contactless communication with a reader. This makes them convenient and quick to use, as they don't need to be physically inserted into a reader. To be read by the reader, the card must be moved to within 2 – 4 inches from the reader. The iCLASS family offers a consistent read range, regardless of body shielding or environmental factors.


  • Magnetic stripe – The magnetic stripe is an optional feature that offers the capability for the card to be more widely accepted with older technology. This is a great option for organizations that have existing magnetic stripe readers and are working to transition to RFID readers.


  • Transaction times – With a typical transaction time of less than 100 milliseconds, these cards provide swift and efficient interactions.


  • Communication Standard – Class cards conform to the ISO 15693 standard. ISO 15693 is an international standard that defines the communication protocol for "vicinity cards," which are RFID cards designed to be read from up to 1 meter away. This is a much greater range compared to "proximity cards," which typically have a read range of up to 10 cm.


  • High frequency – iClass® cards operate at a frequency of 13.56 MHz, which is considered high frequency. This allows for a greater read range and faster data transfer rates compared to lower-frequency systems.


  • Read/Write capability – iClass® cards support read/write operations, which means data can be added or changed on the card after it's issued. This is useful for applications where the data on the card needs to be updated regularly.


  • Security – iClass® cards use a variety of security measures to protect the data stored on the card. This includes mutual authentication, data encryption, and diversified keys, which ensure that each card and reader has a unique encryption key. If more security is needed, the card can be protected with DES or triple DES encryption.


  • Interoperability – The cards can be used with a wide range of readers and systems, making them a versatile choice for access control, identity management applications, and cashless vending.


  • Multi-application support – iClass® cards can support multiple applications on a single card. This means a single card can be used for a variety of purposes, such as building access, payment systems, and employee identification.


  • Printable – iClass® cards can be customized with features such as barcodes and custom images and text.


  • Durability – These cards are designed to be durable and resistant to wear and tear, making them suitable for everyday use. With passive RFID, each card can be read roughly 100,000 times.


  • Visual anti-counterfeit measures – iCLASS® cards can be customized with anti-counterfeiting features, including holograms, UV fluorescent inks, micro-printing, and custom logos.



The iCLASS® classic cards have no additional identifier, they are simply known as iCLASS®. iCLASS® is available in 2k-bit, 16k-bit, and 32k-bit formats.


While these are technically the least secure cards within the iCLASS® family, they are more secure than most proximity cards. iClass cards guarantee a high level of security by using a process where both the card and reader verify each other (mutual authentication), transfer data in a coded form (encrypted data transfer), and use unique 64-bit keys for both reading and writing data.




The next iteration of iCLASS® cards that were released is the iCLASS® SE. With its expansive range of applications, the iCLASS® SE platform is an adaptable solution, well-matched to organizations operating across a variety of physical infrastructures, environmental conditions and climates. iCLASS® SE cards work with SIO-enabled credentials and are available in 2k-bit, 16k-bit, or 32k-bit formats. Currently, there are 8 different subtypes of SE cards. 

These cards are more secure than the classic iCLASS® cards because of the introduction of SIO capabilities. Secure Identity Object (SIO) is a data model developed by HID Global that encapsulates identity information into a single, secured unit.

This information can include various data objects like card numbers for physical access control, fingerprint templates, and cash on card values. The key advantage of SIO is that it ensures related data stay linked together, preventing mismatches like associating one person's card with another's fingerprint. 

The security of an SIO is maintained through a protective wrapper that employs key diversification, authentication signatures, and encryption. This secures the data within, regardless of the device's specific security measures, providing an additional layer of protection. 

The iCLASS® SE card can use the Trusted Identity Platform™ (TIP), a security architecture developed by HID Global that ensures secure identity data transmission. In simpler terms, TIP provides a secure environment for the exchange and verification of digital identity data. If a card is TIP-enabled, it can securely interact with other devices in the TIP ecosystem (like readers, for example), ensuring the integrity and confidentiality of the identity data it carries.


iCLASS® Seos®

HID Global offers four distinct variations of its newest line, the iCLASS® Seos®. These cards are available in 8k-bit or 16k-bit formats. Let's explore their unique features and identify the scenarios where they shine the most.


iCLASS® Seos® 500x

The iCLASS® Seos® 500x high-frequency card offers a dual identity within a single credential. This means it can be used for both physical access control (like opening doors) and logical access control (like accessing IT resources). 

It’s designed to support multiple applications and includes a One Time Password (OTP) feature to enhance security. The cards are programmable and come with a lifetime warranty.

iCLASS® Seo 500x is ideal for organizations that need smart cards that can work across multiple applications and environments.


iCLASS® Seos® + Prox Card 510x

This card integrates both low-frequency (125 kHz) and high-frequency technologies with Seos® capabilities. Like the 500x, it offers dual identity in a single credential and supports an OTP feature. 

It's perfect for organizations with existing access control systems that want to upgrade without completely overhauling their existing setup.


520x iCLASS® Seos®/iCLASS®/Prox

This multi-purpose card is compatible with iCLASS®, iCLASS® SE®, and Prox readers. It offers secure private access via OTP and is a comprehensive three-in-one solution. 

It's best suited for organizations looking to improve security but have budget constraints; they can use these cards while progressively upgrading their systems.


iCLASS® Seos®/iCLASS® 522x

This dual-technology smart card operates with all iCLASS® and iCLASS® SE® readers and supports secure access via mobile devices. It manages multiple applications and provides OTP access to a secure private network. 

These cards are perfect for organizations needing a single solution for two technologies and planning a phased upgrade of their traditional physical access control systems within budget constraints.


Are there cards and keyfobs that are compatible with iClass® card readers?

Sometimes price or availability of iClass® cards presents challenges and an alternative is necessary.  If you are looking for inexpensive cards or key fobs that are compatible with your iClass® card readers, click here for a free sample to test.