Comment by szvsw | Hacker News Reader

Comment by szvsw | Hacker News Reader

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<<<security is not my domain, asking genuine questions!!>>>

At the end of the day, it ultimately still boils down to trust though, yes? Trust that they are running the data centers the way they say they are, trust that their supply chain is what they say it is, and so on? At the same time, using some open source piece of software also entails a great amount of trust: I’m not going through the source code of Signal myself, and I’m also not checking that an open source locally served model isn’t sending traffic/telemetry etc back to some remote server via whatever software is running the model… rather, I’m placing my trust in the open source community that others have inspected and tested these things. I’m sure all sorts of shady PRs into important open source code bases are made on the reg after all. So that’s not to say that trusting Apple is necessarily more or less wise than trusting open source software from a security standpoint… my point is just that it seems like they are aspiring to a zero trust architecture, but at the end of the day, it does still require trust that they are operating in good faith vis-a-vis what they are representing in the white papers right? To me, it seems like a relatively safe assumption that they are for a variety of reasons, but nonetheless, it is an assumption right?

> I’m placing my trust in the open source community

You’re right, security is a matter of degrees not absolutes, but open source software requires considerably less trust than closed source. Right?

PCC applies this principle by making the binaries it runs public and auditable by you or anyone in the security community. (In some cases the source code as well.) The craziness is in the architecture that provides cryptographic proof to clients that the server they’re connecting to is running an audited binary and running on secure hardware. It even does TLS termination at the shard level so you can have high confidence that if the binary isn’t connecting to anything your data will be unreadable by any other server in the org.

So it goes way beyond trusting what the whitepaper says. Data center hardware deployments are audited by a third party that signs the servers in a key ceremony. That ultimately undergirds the cryptographic attestation that servers provide to clients that everything has been audited. And it’s also the element that tighter supply chain control helps shore up.

If you’re new to security the architecture documentation I linked to is a very friendly read and a good intro to some of these threats, countermeasures and rationales.

Thank you for the really great response! It answered my main question:

> The craziness is in the architecture that provides cryptographic proof to clients that the server they’re connecting to is running an audited binary and running on secure hardware.

I definitely missed this concept when skimming the links before posting my comment - very very cool!

> open source software requires considerably less trust than closed source. Right?

Of course… but at the same time, I think the difference in the degree of trust I am placing in say, Signal’s end to end encryption and Apple’s (claims of) end-to-end encryption is not as large as it might cursorily seem. Would I be more surprised to read in the news that Apple had secretly embedded some back door than I would be reading in the news that malicious actor managed to push some hidden exploit through to Signal in an otherwise innocent PR? I’m genuinely not sure which would surprise me more, or which event would be more probable, so can I really make any claim as to which is more secure, given the current knowledge I have? Obviously I could think more deeply about this, but superficially, both are requiring pretty large amounts of trust from me - which I don’t think is misplaced in either… though I do personally trust something like signal more at the end of the day based on… what, intuition? A gut feeling?

That’s good food for thought! I would just add that the kinds of threats PCC is primarily targeting, I think, are attacks by malicious third parties (including state actors), rogue internal employees, and privacy-leaking software bugs. These are sort of bread and butter real world threats.

I would go out on a limb and say Apple would love to also prove beyond a reasonable doubt that they too as an organization cannot get away with planting a secret back door — not because they have pure angelic hearts, but because this is good for their privacy-differentiated business model. And PCC certainly makes a huge leap in that direction. But it’s not the problem it’s primarily targeting nor an easy one to solve completely.

As another example, Apple has an implementation of OHTTP onion routing[1] called iCloud Private Relay. It’s really cool and easy to use. The point is to make it so nobody but you can tell what website your IP address is connecting to, not even Apple, the operator of the relay. But bottom line, Apple picks who they collaborate with for the gateways and there’s nothing stopping them from colluding out of band to de-anonymize you if that’s what they wanted to do.

Does this defeat the purpose of iCloud Private Relay? No. Its purpose is to better protect you from common privacy attacks, better than a traditional VPN would. It happens to also narrow the trust you need to place in Apple, namely that they would need to collude with another company to defeat the system as opposed to some rogue lone wolf SRE deciding to access your logs. But it wasn’t put in place to make people who fundamentally distrust Apple as a company start trusting them.

[1] https://datatracker.ietf.org/doc/rfc9458/

> At the end of the day, it ultimately still boils down to trust though, yes?

Isn't that pretty much the story for most every thing though? It comes down to discernment, which is mostly subjective itself.

Same here. Personally, do I trust Apple? I don't have a leaning one way or another about that. What I trust is that Capitalism is gonna capitalize. And Apple doing what it says here, is its Brand. If down the road it comes out later it was all a lie. That Brand has no more standing. No more standing, no more sales. And Apple is in the Brand/product selling business. I trust they won't throw away their trillions because they would rather sell their Brand on white papers over an actual product that the papers describe.

Yes, I think along similar lines there… but on the other hand, brands need not reflect underlying truths about reality, and in fact often do not. Suppose two years from now, it is revealed by a whistleblower that they were part of a special skunkworks team responsible for creating various backdoors in PCC in order to enable Apple to access the data, train new models on queries, or maybe respond to government requests etc etc, all of which which were subtle, complicated exploits. Maybe Apple denies and discredits, or minimizes, or issues some sort of limited mea culpa. To what extent would it affect Apple’s brand? How long would it stay in the public consciousness? Would people (writ large, not those on HN) care? Perhaps it impacts sales and the stock price, but for how long and to what extent? Obviously there would be some sort of cost to such an event occurring, but would it outweigh whatever benefits that Apple might gain in the meantime? Maybe those benefits have to do with avoiding the wrath of the federal government… who knows. There’s definitely a world where the amoral calculus suggests lying might be better, right? Maybe not ours, but it is plausible. Like you said, discernment is the only tool we have, and it’s difficult to really know what’s going on at the end of the day.

Moscow rules and George Smiley’s tradecraft are probably the only real security… ha!

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