Last revised: October 6, 2024
Reviewed by: Scott Orlosky, consulting engineer

RFID chips use radio signals to transmit data over short distances. They are used typically for security, tracking, monitoring and identification purposes. RFID chips can be paired with other circuitry to create tags or readers that also use radio frequency identification (RFID) technology.

RFID chips wirelessly transmit their unique serial-number identifiers, even when embedded in objects such as clothing or currency. When an RFID reader broadcasts a request for this information, the RFID tag that contains the corresponding ID code responds with a transmission. Some of these RFID devices do not have batteries, and are instead powered by the radio signals themselves.

This diagram shows the role of an RFID chip in a transponder.

Image Credit: RFID Handbook

Types of RFID Chips

The Engineering360 SpecSearch database categorizes RFID chips according to the type of device (passive, active, or semi-passive) in which the chips are used.

• Passive devices are RFID tags without batteries. They draw power from the magnetic field that is created when radio waves reach the chip's antenna. Using this generated power, passive RFID devices transmit information that is stored on the chip.
• Active devices are RFID tags that use a battery to power the microchip's circuitry and transmit a signal to the reader. Active tags can be read from distances of 100 ft. or more.
• Semi-passive devices are similar to active tags, but only use the battery to run the microchip's circuitry. To communicate with the reader, these tags draw power from the magnetic field that is created. Some semi-passive tags "sleep" until "awakened" by a signal from the reader.

Suppliers may also designate their products as encrypted or short-range.

Specifications

There are multiple standard protocols controlled by ISO, IEC and EPCGlobal that have been established. A partial list is shown below. Check on line for current standards at each of these agencies. Some protocols are designated for specific use (animal tagging, or automotive industry for example). RFID chips may be equipped with a serial, wireless, TTL, or I2C interface. Frequency, memory, read rate, detection range and operation temperature are the key performance specifications to consider. When specifying the frequency, industrial buyers should note that products use low, high, ultra-high and microwave frequencies. Each has advantages and disadvantages, depending upon the user's application.

Features

Like other types of radio frequency identification (RFID) products, some chips can operate without physical contact between the tag and the reader. Portability, encryption, and continuous reporting are also important features to consider, depending upon the application.

RFID Chips FAQs

What are the privacy concerns associated with RFID chips?

Privacy concerns include the potential for unauthorized tracking and data collection. Citizens are wary of the loss of control over personal information and the potential misuse of RFID technology.

What are some applications of RFID technology?

RFID technology can be used for making purchases, opening doors, using copy machines, logging into computers, unlocking phones, sharing business cards, storing medical/health information, and as a form of payment at RFID terminals.

What are the different types of RFID chips based on data manipulation capabilities?

RFID chips can be read-only, WORM (Write Once Read Many), or read-write. Read-write chips allow data manipulation by the user's system and are generally more expensive due to their versatility and subsequent complexity.

What are the cost implications of using RFID tags?

Passive RFID tags are exceptionally cheap, often costing less than around $0.10 each. Active tags are more expensive but offer additional functionalities that justify the cost.

What are some of the encryption methods used in RFID technology?

Encryption methods used in RFID technology are crucial for ensuring the security and integrity of data transmitted between RFID tags and readers. Here are some key aspects of encryption in RFID technology:

Data Encryption

Encryption is used to encode the data transmitted between the RFID tag and the reader, making it difficult for unauthorized parties to intercept and understand the information.

Implementation: Suppliers may designate their RFID products as encrypted, which means that the data is protected by cryptographic algorithms during transmission.

Types of Encryption

Symmetric encryption: This method uses the same key for both encryption and decryption. It is faster but requires secure key management since both the tag and the reader must share the same key.

Asymmetric encryption: This method uses a pair of keys – a public key for encryption and a private key for decryption. It is more secure but computationally intensive, making it less common in low-power RFID systems.

Encryption Algorithms

Common encryption algorithms used in RFID technology include AES (Advanced Encryption Standard), DES (Data Encryption Standard), and RSA (Rivest-Shamir-Adleman). These algorithms vary in terms of security level and computational requirements.

Challenges and Considerations

Encryption can add computational overhead, which may affect the performance of RFID systems, especially in low-power or passive tags.

Securely managing and distributing encryption keys is critical to maintaining the security of RFID systems. This includes generating, storing, and updating keys as needed.

Ensuring that the encryption methods used are compatible with the existing RFID infrastructure and standards is essential for seamless operation.

Applications

Encrypted RFID chips are used in various applications where data security is paramount, such as access control, payment systems, and secure identification.

These encryption methods collectively enhance the security of RFID systems, protecting against unauthorized access and ensuring the integrity and confidentiality of the data transmitted.

What are the differences between read-only, WORM, and read-write RFID chips?

Here are the differences between read-only, WORM, and read-write RFID chips:

Read-Only RFID Chips

These chips are pre-programmed with data during the manufacturing process, and this data cannot be altered or updated. They are ideal for applications where the data does not need to change, such as asset tracking or identification tags.

Since the data cannot be modified, it provides a higher level of data integrity and security against unauthorized changes.

WORM (Write Once Read Many) RFID Chips

These chips allow data to be written once after manufacturing, but once written, the data cannot be changed. They are suitable for applications where data needs to be recorded once and remain unchanged, such as recording the date of manufacture or a unique identifier.

These chips offer a balance between flexibility and security, ensuring that once the data is written, it remains tamper-proof.

Read-Write RFID Chips

These chips allow data to be written and updated multiple times by the user's system. They contain a unique identifier from the manufacturer but also have an updateable database where data can be added or modified.

They are used in applications requiring frequent updates to the stored data, such as inventory management, access control, and dynamic data logging.

These chips are generally more expensive than read-only or WORM chips due to their versatility and the additional functionality they provide.

While offering greater flexibility, these chips require robust security measures to protect against unauthorized data manipulation.

Read-write chips are particularly versatile and are open to data manipulation by the user's system without restrictions, making them suitable for dynamic applications but also necessitating stronger security protocols to ensure data integrity.

RFID Chips Media Gallery

Resources 

GlobalSpec— RFID: Automatic Identification Evolves

GlobalSpec—RFID Tags

GlobalSpec— Some U.K. Companies to Consider Microchipping Employees

Infineon - Object Identification

Atmel - RF Identification