This is the moment you’ve been waiting for. You’re over halfway through this blog series and just now using the TPM for its true purpose. It’s time to encrypt!

This is a quick post (because TPMs are so simple to use!). In Parts 1 & 2, we set up a RaspberryPi with an OPTIGA SLB9670 TPM2.0 eval board. Then, we poked around and got familiar with the concept of “handles” in TPMs. Now let’s write something of our own to a new handle in non-volatile memory.

Let’s read some non-volatile data out of the TPM that we had set up in Part 1. “Wait, read data out of a TPM?!?” you might ask? Yes, you can read a lot of information from a TPM. Read on for more info!

Trusted Platform Modules (aka TPM or TPM2.0), store digital keys in a secure way. There is no way for anyone to read keys from a TPM. This high-level information is common knowledge.

But how does a developer actually use a TPM? Most public information regarding TPMs is either very high-level, or so low-level that it’s not helpful to learn from. This blog post will explain with mid-level technical depth & hands-on examples.

At Summit Embedded, a core part of working efficiently is to enable our employees to work from anywhere. Embedded devices aren’t very portable. We’ve found that remote embedded devices need to be physically power cycled from time to time. For this, we connect USB-Controlled Relays in-line with the power supply to each device. This post details a few tweaks that we made to the open-source HID driver called usbrelay to get it working for our setup.