Secure NFC/RFID tag authenticator with energy harvesting

November 05, 2014 // By Graham Prophet
Protecting sensitive data transfer between master and slave devices, Maxim Integrated’s MAX66242 DeepCover Secure Authenticator authenticates, configures, and collects data from any embedded system through its NFC/RFID wireless data communication and simple I²C interfaces.

The MAX66242 secure authenticator is an advanced tag that combines a wireless NFC/RFID interface with an I²C interface. Designers can now collect vital system data from portable devices even when the main energy source on the master device is not functional. The I²C and wireless RFID/NFC interfaces make it highly flexible and scalable for a wide range of applications. The MAX66242 is especially useful for applications that require additional external functionality, but do not have the space to place a connector. Ideal applications include secure, wireless transfer of medical data or asset tracking.

The MAX66242 enables wireless, contactless data collection between a host and slave device. The integrated SHA-256 cryptographic engine provides symmetric challenge-and-response authentication based on a secret key for data downloads. Needing no separate controller to write data, the MAX66242's I²C interface port can operate as a master port or a slave port for secure data exchanges. The MAX66242 comes with multiple memory programmable options which let a user configure a secure master/slave system and set usage limits using the EEPROM emulation mode to create nonresettable counters. Designers can also use the MAX66242 to set up easy and intuitive WiFi or Bluetooth connections as a means to securely storing the pairing codes. It then provides security for access control, asset tracking, system alert/wakeup, and authentication of medical sensors for the secure transfer of personal data.

The MAX66242 does not require an external power source. Instead it integrates an energy harvesting capability that can be used to power surrounding ICs such as a temperature sensor, to which it is connected to via the I²C interface. Using this harvested energy, the MAX66242 provides the energy source to the slave device and gathers data from it. The energy harvesting feature also complements the existing power source in battery-powered devices, so it will extend overall battery life.

Secure authentication : integrated SHA-256 die-level protection prevents cloning, counterfeiting, and data theft in applications