But in this case the mechanics at play are the same: people can read the documentation and arrive at the idea that this protocol is actually good and much better than some alternatives.

Instead, they form an opinion based on generic distrust for apple and Google, just like no-vax people do it out of generic mistrust for institutions and big pharma.

While the protocol may be good, the app implementing it may be not. Google and Apple have gone to great length that you cannot control what's running on your device. The next update can be nefarious and you can do only little about it. Just have a look at the Australian assistance laws. The distrust is well earned.

but the next OS update can do whatever it wants too, how is this a change? We will always need independent verification and observation of the platform behaviour from the outside.

The distrust _is_ justified, and we should be wary. What is not justified is dismissing the CTF based only on that, imo.

While that might be an argument in general, the protocol Google and apple are working in is cryptographically secure. They provably can't back out data about you.

Is their code open source? How do you know this?

Yes.

https://www.apple.com/covid19/contacttracing/

A PDF document with a specification is not even close to "open source code". There is no way to know whether the specification actually matches the implementation.

> There is no way to know whether the specification actually matches the implementation.

That would be true even if Apple suddenly decided "oh these folks on HN want to see the code for that tracing component, better open source our complete OS". I've seen assurances that parts of this will be open sourced as far as they can but I honestly don't see how that matters. You have, as is a general tradition, a description of what this system does cryptographically. The rest is a matter of reverse engineering that hardly benefits from having the code. It's not like Play store updates or whatever Apple uses to push this are reproducible builds the end user can verify. And you always have the closed source blob of whatever BTLE chipset your device uses which you can mistrust.

edit: Let me qualify "but I honestly don't see how that matters" for the question of trust in what runs on your phone here. If you read a dig at OSS into this you're generalizing far over what I'm addressing here.

There are defiantly benefits from having the source code when it comes to being able to verify that the implementation does in fact match the specification. Sure, reverse engineering the binary would be possible but far more difficult. Reading open source code is far easier than reverse engineering. (Added in edit: From what I've read, the spec itself doesn't seem bad. The point is, assurance that does not require trust in another entity that the spec was implemented as written would drastically improve the confidence in the system.)

I have compiled some of the apps on my phone myself so I know that the result does in fact come from the same source code. That may not work in the case of iOS devices, though.

> And you always have the closed source blob of whatever BTLE chipset your device uses which you can mistrust.

That is a good point and it'd be great if that chipset could also be open sourced but one step at a time.

> That would be true even if Apple suddenly decided "oh these folks on HN want to see the code for that tracing component, better open source our complete OS".

You are correct if it was simply open sourcing the OS. If it was possible to compile and install the OS ourselves, that would completely change the game.

> but I honestly don't see how that matters

https://www.gnu.org/philosophy/free-sw.html

There is no code available at that link, and no indication whatsoever that Google and Apple’s implementation of the algorithms and protocols described in those documents will be open source.

I believe your claim is false.

Realistically, those APIs will be analysed soon after they're available in the same way COVIDSafe was. If they do something different than what's in the design, we'll know pretty quickly.