Abstract
This article presents NFC-enabled security solutions using Analog Devices’ DeepCover secure authenticator with SHA-3-based challenge-response authentication along with the transponder to authenticate, track, and manage consumables in medical, consumer, and industrial systems—protecting against counterfeits and unauthorized reuse across various form factors.
Introduction
In today’s interconnected world, secure authentication is essential for protecting critical data, safety-related information, and authenticated consumables across industries. From healthcare to consumer electronics to industrial environments, verifying the authenticity and integrity of components is paramount. Secure authenticators help devices reject unauthorized, counterfeit, or expired components that could compromise quality, safety, or regulatory compliance. With growing concerns over data security and product authenticity, companies are seeking advanced solutions to ensure the integrity of their systems.
Among available technologies, near field communication (NFC) offers a practical solution for close range, contactless interaction without a large power supply. Positioned between wired and wireless systems, NFC provides benefits for portable or consumable products that require frequent replacement or movement. Wired connections, dependent on physical connectors and cables, can be unreliable in applications such as industrial filters or medical infusion pumps, where vibration and wear can cause disconnection or failure. NFC’s contactless design eliminates physical wear points, improving durability, reliability, and ease of component replacement—particularly when authenticated parts are swapped or handled regularly.
NFC also has advantages over wireless methods like Wi-Fi and Bluetooth®. While these alternatives provide broader connectivity, their longer range increases the potential attack surface, requiring robust encryption to prevent interception or unauthorized access. NFC’s short range—typically a few centimeters—supports secure, deliberate interactions at the point of use. It is also low power, allowing tags or transponders to be passively powered by the reader. Unlike Wi-Fi or Bluetooth, which require ongoing power, NFC remains dormant until activated, improving energy efficiency.
The MAX66301 DeepCover® secure authenticator combines NFC with SHA-3-based challenge-response authentication to protect against unauthorized access and counterfeits. Paired with the MAX66250 transponder, it offers features to prevent counterfeit products, monitor consumable lifespan, and track usage history. Together, these devices provide secure authentication where traditional NFC tags lack adequate protection against tampering, unauthorized use, and cloning.
In this article, we examine how these devices can safeguard critical systems. By integrating advanced cryptographic features and secure data storage, these devices address the needs of applications requiring authentication, controlled expiration, and usage monitoring. Let’s first review NFC technology and its limitations, then three real-world use cases that highlight the benefits of this solution will be presented.
Introduction to NFC Technology
What Is NFC?
NFC is a short-range wireless communication technology that allows devices to exchange data when they are brought within close proximity, typically a few centimeters. NFC operates at a frequency of 13.56 MHz and is widely used in contactless payment systems, secure access, and product authentication. Although some NFC protocols fall under the NFC umbrella without being ISO/IEC compliant, most implementations follow ISO/IEC standards (14443 and 15693) to ensure compatibility and ease of integration across industries.
How NFC Works
NFC operates through magnetic induction between two devices: a reader and a tag. The reader’s antenna generates an alternating magnetic field that powers a passive tag by inducing current in its coil. Once powered, the tag can send data back to the reader by modulating the magnetic field—a method known as load modulation—while the reader sends data using amplitude modulation. This arrangement enables a compact, power-efficient design in which the tag draws only a small amount of energy, typically in the microwatt to low milliwatt range, to perform its operations.
Security Limitations of NFC
While NFC offers convenience and flexibility, it also has inherent security limitations:
- Short-Range Security Risks: Even with close proximity requirements, NFC can still be vulnerable to eavesdropping, interception, and relay attacks.
- Counterfeit Tags: Without robust authentication, unauthorized or counterfeit tags can bypass protections.
- Data Integrity Risks: Standard NFC tags may lack mechanisms for secure expiration tracking or usage history.
The MAX66250 secure authenticator tag addresses these vulnerabilities with three key features: robust authentication, controlled expiration, and secure usage tracking. At the heart of its security is SHA-3-based challenge-response authentication, in which the reader sends a random challenge to the tag, the tag uses a secret key to compute a cryptographic response, and the reader verifies it. Only matching responses confirm the tag’s authenticity.
To manage the lifecycle of consumable products, the device also includes a 17-bit one-time settable, nonvolatile decrementonly counter with authenticated read—meaning the counter value can only be accessed after successful authentication, preventing tampering or unauthorized resets. Historical usage tracking is reinforced with secure storage for sensitive data, 256 bits of secure EEPROM for user data, and cryptographic protection that blocks unauthorized access or discovery. Together, these features create a multilayered solution for authenticating, monitoring, and managing critical applications that demand the highest security and integrity.
For a deeper understanding of NFC technology, refer to the “Secure Microcontrollers NFC Overview” app note.
Examples of Use Cases
NFC-enabled secure authenticators like the MAX66250 have applications across many industries where secure, contactless interactions are essential. In healthcare, industrial manufacturing, consumer electronics, and logistics, the demand for authentication, controlled access, and tamper prevention is growing. From verifying consumables in medical devices to ensuring only authorized personnel can access restricted areas, NFC authenticators provide a practical, power-efficient solution for robust security.
As industries face counterfeiting, unauthorized usage, and strict compliance requirements, the need for more secure NFC technology grows. Traditional NFC tags often lack advanced features, making them vulnerable to cloning, modification, and data interception—a particular concern in critical applications where authenticity directly impacts safety and quality. The MAX66250 meets these needs with bidirectional SHA-3 authentication, controlled expiration, and usage tracking, offering security beyond standard NFC. The following sections explore three real-world use cases where these features enhance security, reliability, and compliance.
1. Medical Infusion Pump
Medical infusion pumps are essential in healthcare, delivering precise medication dosages over controlled intervals. These systems depend on consumable components, such as medication cartridges, which must be replaced periodically to maintain their accuracy and reliability. However, the absence of a secure mechanism to authenticate these consumables presents several risks, ranging from counterfeit cartridges to operational failures caused by contamination or unmonitored usage.
Counterfeit consumables pose a serious threat to patient safety. Unauthorized medication cartridges can introduce inaccuracies in dosage delivery, compromising treatment efficacy and even the patients’ health. In addition to these safety risks, the internal components of the pump itself are vulnerable to damage from fluid contamination. Traditional electromechanical interfaces, commonly used in such systems, rely on physical connections that can degrade over time, allowing fluids to leak and damage internal elements. NFC technology provides a critical advantage in this context by offering a contactless solution, mitigating the risks associated with physical interfaces while ensuring a secure communication channel between the pump and its consumables.
A proposed solution integrates the MAX66301 NFC reader and the MAX66250 NFC tag to address these vulnerabilities comprehensively (see Figure 1). The MAX66301 is embedded within the pump’s cartridge barrel, driven by the system’s microcontroller, which also manages the pump’s actuation. Medication cartridges are equipped with the MAX66250 NFC tag, either attached externally or embedded directly into the cartridge. When the cartridge is inserted into the pump, the MAX66301 reader initiates a challenge-response authentication process with the tag. Only upon successful authentication is the pump enabled, ensuring that only genuine cartridges are used. See Figure 2.
In addition to robust authentication, this solution supports controlled expiration and usage tracking. The MAX66250 includes a 17-bit one-time settable, nonvolatile decrement-only counter with authenticated read, allowing the system to enforce expiration dates or usage limits for cartridges. For example, expiration can be determined by either time elapsed or the number of uses, ensuring that consumables are replaced within their safe operational periods. This data, along with details such as the cartridge’s date of creation, first use, and total usage count, is securely stored within the EEPROM. This cryptographically protected storage uses encryption and authentication to ensure that data cannot be altered or read without proper authorization, making it tamper-proof and providing an auditable usage history that does not require external connectivity.
By integrating NFC technology, this system not only enhances security and reliability but also simplifies operation for healthcare professionals and patients. The absence of physical connectors minimizes wear and tear, while the contactless design reduces the risk of internal fluid contamination, protecting the pump’s critical components. Furthermore, the NFC-enabled solution enables seamless and secure cartridge replacement, allowing users to maintain the pump’s functionality with minimal effort.
While automatic disabling of expired consumables may not always be practical, the system can issue prominent alerts to indicate the need for replacement. In critical cases, the pump can enforce bypassable blocking, preventing actuation until a valid cartridge is installed. This flexible approach balances safety and usability, ensuring that healthcare providers can prioritize patient care without compromising on security.
The integration of the MAX66301 and MAX66250 establishes a new standard for infusion pump security, addressing critical vulnerabilities while providing a user-friendly and contamination- resistant solution. This NFC-enabled system exemplifies the transformative potential of secure authentication technology in medical applications, enhancing both patient safety and operational reliability.
2. Consumer Water Filters (Such as Fridge Filters)
Building upon the design principles developed for medical infusion pumps, a similar NFC-enabled solution can be applied to water filtration systems in refrigerators. These systems, like infusion pumps, rely on consumable components—water filters—that must be periodically replaced to maintain quality and safety. However, they face comparable challenges, including counterfeit consumables, lack of authentication mechanisms, and insufficient tracking of usage or expiration.
The NFC-enabled design, which integrates the MAX66301 NFC reader into the filter housing and the MAX66250 NFC tag into the water filter cartridge, ensures that only authorized filters can be used. When a new filter is inserted, the NFC reader initiates a challenge-response authentication process with the tag. Upon successful authentication, the system validates the filter and allows water flow. See Figure 3.
A key feature of both the medical pump and water filter designs is the innovative use of a cylindrical solenoid antenna that generates a toroidal NFC field, enabling robust communication between the reader and the tag. This toroidal field ensures reliable authentication on curved surfaces, eliminating the need for precise alignment between the reader and tag antennas. By wrapping the solenoid antenna around the cylindrical holder at a fixed distance from the cartridge’s NFC tag, the design allows seamless interaction regardless of the tag’s orientation.
The tag adds further functionality by supporting controlled expiration and usage tracking. The 17-bit one-time settable, nonvolatile decrement-only counter with authenticated read enables enforcement of expiration dates or tracking of usage, such as the total volume of water filtered. Secure EEPROM allows critical data storage, including the date of installation, first use, and total usage history, providing a comprehensive record for maintenance and replacement. This data is protected by cryptographic mechanisms, ensuring it cannot be tampered with or accessed by unauthorized parties.
Operationally, this NFC-enabled design enhances durability and reliability. By eliminating physical connectors, the solution minimizes wear and tear in high moisture environments, where traditional connections may degrade over time. Furthermore, the toroidal NFC field ensures consistent authentication performance without requiring precise alignment, greatly simplifying cartridge replacement for consumers.
When a filter approaches its expiration or exceeds its safe usage limits, the system can alert users through the refrigerator’s interface or a connected app. For critical scenarios, the design can enforce bypassable blocking, preventing water flow until a valid filter is installed. This ensures that water quality is maintained while giving users the flexibility to replace filters as needed.
By extending the secure authentication framework of the medical pump to water filters, this implementation highlights the versatility and adaptability of the MAX66301 and MAX66250 pairing. The introduction of the toroidal NFC field concept on curved surfaces further refines the design, demonstrating how robust authentication, controlled expiration, and historical usage tracking can be seamlessly integrated into everyday appliances. This NFC-enabled system provides a significant advancement in water filtration technology, ensuring safety, authenticity, and ease of use.
3. Industrial HEPA Filters
The versatility of NFC technology extends beyond cylindrical designs like those used in medical infusion pumps and water filters. In industrial applications, NFC’s adaptability enables secure and reliable integration even on flat surfaces, as demonstrated in the implementation for HEPA filters. Industrial HEPA filters are critical for maintaining air quality in environments such as cleanrooms, pharmaceutical manufacturing, and food processing. These filters are often subjected to rigorous use, and their performance directly impacts safety and compliance. However, current tracking mechanisms, such as light sensors that measure filter dirtiness, are insufficient for ensuring quality and safety.
A common issue with light-based sensors is their susceptibility to manipulation. Filters can be cleaned and reinstalled, tricking the sensor into resetting the usage data. While this may appear cost-effective, it significantly reduces the filter’s effectiveness and endangers users by allowing degraded filters to remain in operation. To address this vulnerability, the NFC-enabled solution integrates a secure authentication and usage tracking mechanism that cannot be modified or bypassed by third parties.
This design incorporates the MAX66301 NFC reader into the filter housing and the MAX66250 NFC tag onto the flat surface of the HEPA filter (see Figure 4). By leveraging the flat geometry, the NFC tag is securely attached in a fixed position, ensuring consistent and robust communication. The challenge-response authentication process confirms the filter’s authenticity before operation, ensuring that only authorized filters are used. Unlike light-based sensors, the usage data stored on the tag is cryptographically protected, making it immune to tampering or unauthorized modification.
The MAX66250 also enables precise usage tracking, ensuring that filters are replaced at appropriate intervals. Rather than relying on environmental measurements like dirt accumulation, this implementation directly tracks the filter’s lifecycle through authenticated data stored in secure EEPROM. The stored information includes the filter’s installation date, first use, and total operational hours or cycles, providing a reliable and tamper-proof record of usage—meaning the record cannot be altered without cryptographic authorization. This approach eliminates the risks associated with filter reuse and ensures that degraded filters are never reinstated into the system.
Operationally, the flat-surface NFC implementation offers several advantages. The lack of physical connectors or mechanical interfaces improves durability and simplifies installation, even in high vibration industrial environments. Additionally, the compact design of the NFC reader and tag allows for seamless integration into existing filter housings without requiring significant modifications.
By implementing NFC-enabled authentication and tracking, industrial HEPA filter systems can ensure compliance with air quality standards while protecting users from the risks posed by counterfeit or improperly maintained filters. This solution extends the dynamic nature of NFC technology, demonstrating its adaptability to various geometries and environments. From cylindrical cartridges to flat filters, the MAX66301 and MAX66250 pairing provides a robust, flexible foundation for enhancing safety, reliability, and operational efficiency across diverse applications.
Conclusion
In applications where security, safety, and compliance are essential, the MAX66301 and MAX66250 pairing offers a comprehensive NFC solution for secure authentication, expiration control, and usage tracking. Through the highlighted use cases—medical infusion pumps, consumer water filters, and industrial HEPA filters—this technology addresses unique vulnerabilities, ensuring product integrity and enhancing user safety. This NFC-enabled secure authentication system is poised to set new standards for secure, efficient operations in various industries.