MAXREFDES143

Introduction

In this IoT-embedded world, security emerges as a paramount feature to protect industrial equipment from counterfeiting while tracking product lifetime with smart notifications. The MAXREFDES143# is a reference design that demonstrates an authenticated data chain from a protected sensor node to a web server. There are notifications to the user through the web server when intervention is required such as when it is time to change the consumable being monitored (i.e., the protected sensor node), a filter in this case, or if an unsafe consumable (i.e., counterfeit sensor node) is installed.

The simplicity of this design enables rapid integration into any star-topology IoT network requiring the heightened security with low overhead provided by the SHA-256 symmetric-key algorithm.

NOTE: Operating the MAXREFDES143# requires a separate purchase of a MAX32600MBED# ARM^® mbed^™ platform.

Detailed Description of Hardware

The system in Figure 2 shows the high-level implementation of the design. The reference design sequence is as follows:

The mbed Platform uses the DS2465 to authenticate the DS28E15 on the Sensor Node. For details, refer to application note 5546, "The Fundamentals of a SHA-256 Master/Slave Authentication System."

1. The Sensor Node measures temperature using the DS7505 and simulated filter life using the MAX44009, which measures light illuminating through the filter when requested from the mbed Platform.
2. The mbed Platform uses the DS2465 to perform an Authenticated Write to filter life stored on the Sensor Node if necessary.
3. The mbed Platform requests a challenge from the Web Server to prevent replay attacks.
4. Use the DS2465 and the mbed Platform to formulate a MAC from the following components: formatted sensor data, a Transport Secret derived from the Master Secret, and received challenge from the Web Server.
5. The mbed Platform sends sensor data and the newly formulated MAC to the Web Server using a Wi-Fi connection.
6. The Web Server verifies MAC, adds authentic sensor data to the log, and distributes alerts if necessary.

Hardware Setup

• MAXREFDES143# kit including shield, Protected Sensor Node module, and ESP8266 Wi-Fi module (available for purchase)
  • Available for immediate download on the Design Resources tab is the schematic, BOM, and PCB Gerber.
• MAX32600MBED# (ARM® mbed Enabled Development Platform for MAX32600—available for purchase separately) used as embedded microprocessor for the mbed Shield
  • MAX32600MBED Product Folder
• USB A to USB Micro-B cable

Software Setup

• PHP example web application is available for immediate download on the Design Resources tab.
• Firmware files are available from the ARM mbed Developer Site found here:
  • https://developer.mbed.org/teams/Maxim-Integrated/code/DeepCover-Embedded-Security-in-IoT/

Pinout

Figure 2 shows the shield pins (e.g., J3 to J6) that connect to the mbed Platform (e.g., MAX32600MBED#).

Figure 3 shows the shield connections to the ESP8266 WiFi socket (J1), the Protected Sensor Node (J2), the three pushbuttons (i.e., SW1 to SW3), the RED LEDs (D1 and D2) and the LCD (part # NHD-C0220BiZ-FS(RGB)-FBW-3VM).

Quick Start

Required equipment:

• Any PC or notebook computer with an internet browser and a free USB port
• MAXREFDES143# board
• MAX32600MBED# or equivalent mbed platform
• USB A to USB Micro-B cable

Download, read, and carefully follow each step in the appropriate MAXREFDES143# Quick Start Guide.