LetsTrust TPM for Raspberry Pi

LetsTrust TPM is an easy-to-use TPM (Trusted Platform Module) solution for the Raspberry Pi, based on the Infineon Optiga ™ SLB 9670 TPM 2.0.

A hardware TPM can be used in a variety of ways, including for authentication/signatures, storing crypto keys and much more. The module can also be used as a True Hardware Random Number Generator (TRNG) if you need a good source of randomness!

LetsTrust TPM uses the SPI interface to communicate with the Raspberry Pi. It is compatible with all Raspberry Pi models - Model B, Model A, Pi Zero and Pi400 (with cable).

It has a compact footprint allowing the remaining GPIO pins to be used. 2x5 pins from pin 17 to pin 26 are occupied by LetsTrust.

Note: Raspberry Pi not included

Specifications

TPM features

• Infineon Optiga ™ SLB 9670 TPM 2.0
• Compliant with TPM Specification 2.0 Rev. 01.38
• Firmware> = 7.85
• TRNG (Real Random Number Generator) - True Hardware Random Number Generator

Design & interface

• Interface to the Pi: SPI
• Compatible with all previously released Raspberry Pi models (including Pi 3, Pi Zero, etc.)
• Compact size thanks to 2x5 pin headers, so the remaining GPIO pins remain freely available
• Can be firmly soldered with Raspberry Pi pins
• Fits into common standard housings

Software support

• From Raspbian Stretch upwards, with kernel 4.14.85 built-in support with a device tree overlay
• Built-In Support for Windows 10 IoT (on Pi 2, 3, 3B +)

Package Contents

• 1x LetsTrust TPM module
• 1x 8-pin header (installation aid to determine the correct position for the TPM module without counting)

Resources

• TPM2 software
• ELTT2 Infineon Embedded Linux TPM Toolbox 2 for TPM 2.0 - test, diagnostics, etc. for the Infineon TPM chip
• Script examples for getting started & installing the TPM 2.0 tools
• Further information and links can be found at www.LetsTrust.de

Installation

Step 1: Attach the 8-pin header to pin 1 of the Raspberry Pi

The pin header has pins at the top that can be used directly for other projects if necessary. Attaching the 8-pin header is used to determine the correct pins for attaching the LetsTrust TPM module and is not required for its function.

Step 2: Plug in the LetsTrust TPM module

The module is plugged directly next to the 8-pin header.

Notes

• Software installation necessary to use the module - see letsTrust.de from Rasbian with Kernel 4.14.85 DTO support
• The module also works with Windows 10 IoT Core (Pi 2, 3, 3B + supported)
• The module is delivered with firmware> = 7.85