hckrnws

I worked on OpenTitan for around 5 years at lowRISC. It certainly has its ups and downs but it's generated some great stuff and I'm very glad to see hit proper volume production like this. Whilst there's definitely open source chips out there and lots more using bits of open source that don't actually advertise this fact I believe this is the first chip with completely open RTL that's in a major production volume use case.

One of highlights working on OpenTitan was the amount of interest we got from the academic community. Work they did could actually get factored into the first generation silicon making it stronger. Ordinarily chips like that are kept deeply under wraps and the first time the wider security community can take a look at them development has long completed so anything they might find could only effect generation 2 or 3 of the device.

Academic collaboration also helped get ahead in post quantum crypto. This first generation chip has limited capabilities there but thanks to multiple academics using the design as a base for their own PQC work there was lots to draw on for future designs.

I'm no longer at lowRISC so I don't know where OpenTitan is going next but I look forward to finding out.

I'm not seeking to criticise this product, I think this is a great development.

But, for almost all people this is shifting from one kind of "trust me bro" to .. another. We're not going to be able to formally prove the chip conforms to some (verilog?) model, has no backdoors, side channels, you-name-it. We're in the same place we were, with the same questions. Why do we trust this and the downstream developments? Because we do.

To be more critical my primary concern will be how deployment of this hardware is joined by significantly less benign design choices like locked bootloaders, removal of sideloads. To be very clear that's a quite distinct design choice, but I would expect to see it come along for the ride.

To be less critical, will this also now mean we get good persisting on device credentials and so can do things like X.509 certs for MAC addresses and have device assurance on the wire? Knowing you are talking to the chipset which signed the certificate request you asserted to before shipping is useful.

Clicking through links eventually led to https://lowrisc.org/ibex/ -

> Ibex® is a small and highly configurable open-source RISC-V embedded processor available under an Apache 2.0 licence. It is formally verified and very well validated, and it has excellent toolchain integration, which has led many companies to use it in their commercial SoCs.

> [...]

> Ibex is the main CPU in the OpenTitan® root of trust, which has brought the quality of the design and documentation to new heights.

So that's neat.

This is really great. OpenTitan has some useful IP components that can definitely be reused, and it's really cool that this is open. Nice one Google. I have to minority nitpick though:

> both individual IP blocks and the top-level Earl Grey design have functional and code coverage above 90%—to the highest industry standards—with 40k+ tests running nightly

This is definitely not "to the highest industry standards". I've worked on projects where we got to 100% on both for most of the design. It's definitely a decent commercial standard though - way above most open source verification quality.