The NervesKey is a tiny circuit board with an ATECC608A cryptographic chip from Microchip Technology. It is an inexpensive addition to the Raspberry Pi and other embedded computing platforms that include an I2C bus.
The production NervesKey board contains the tiny 'UDFN' version of the part ATECC608A-MAHDA and a 0.1uF 0402 size capacitor. These boards are not easily assembled, so they are professionally manufactured in high quantity for the Nerves project and offered for sale in low quantity by Nerves contributor Troodon Software, LLC.
Mounting to a Raspberry Pi
The easiest way to outfit a Raspberry Pi with a NervesKey is to solder it to the 'hat' expansion header on the bottom of the board as shown below. This will connect the appropriate signals and keep the board out of the way of other uses of the hat header. The NervesKey board is thin to support this application.
See the schematic for additional hardware details, notes, and examples.