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Comment by Scene_Cast2 | Hacker News Reader

I see that there's a lot of mindshare on privacy and "computing trust" these days. There are several approaches that I noticed. One is to not send data to untrusted places (e.g. a server), another is to have a trust chain & hardware enclave (either through SGX / trustzone), and lastly to encrypt data (e2e encryption for transport-only, or homomorphic encryption (slow) / distributed encryption) for doing operations on the data. Currently, verifiable OSS on the server isn't in vogue (in practice or literature), but could be another approach.

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It's a societal dead end, so there's no technical excitement. The same technology that would let you verify a cloud server is running code you specify, would also be used by websites to demand that your personal computing environment conforms to their whims.

Imagine websites that required proprietary Google Chrome on Win/OSX on bare metal - no VM, no extensions, no third party clients, no automation, etc. Imagine mandatory ads, unsaveable images, client-side form verification, completely unaccountable code, etc.

Protocols are the proper manner of allowing unrelated parties to transact at arm's length, and technologies such as remote attestation would completely destroy that.

> Imagine websites that required proprietary Google Chrome on Win/OSX on bare metal - no VM, no extensions, no third party clients, no automation, etc.

No need to imagine, we already have that: it's called fingerprinting. Mainly via WebGL.

There is a major difference between something being difficult/annoying, and outright impossible.

Memory tagging looks interesting to me.

This paper from LowRISC outlines the possibilities pretty well: https://riscv.org/wp-content/uploads/2017/05/Wed0930riscv201...

Referencing that not to plug RiscV, but solely because it's a good explanation. I would guess Intel, AMD, and ARM have plans or some existing work going on.

Memory tagging is already been used successfully for years on Solaris SPARC,

https://docs.oracle.com/cd/E37838_01/html/E61059/gqajs.html

In what concerns ARM, all Android 11 and later versions are going to support it.

https://security.googleblog.com/2019/08/adopting-arm-memory-...

https://source.android.com/devices/tech/debug/tagged-pointer...

Unfortunelly Intel's MPX was a failure, for reasons, however the rest of the CPU vendors seems to be going into the C machine model, as only way left to fix the language.

Verifiable OSS doesn’t stop a malicious operator from just looking at your bits in memory

> I see that there's a lot of mindshare on privacy and "computing trust" these days.

This is the opposite of respecting privacy (unless you mean e.g. the privacy of DRM code), all of this stuff is "trusted" as in TCG.

https://signal.org/blog/private-contact-discovery/ seems like an application of SGX where net privacy is increased.

Or, that looks like a single point of failure that would make a good target for the government to issue a National Security Letter to Intel for.

It’s better than before, where all that stuff was available in plaintext

Signal didn't back up contacts and settings to their servers until they implemented "Secure Value Recovery", which relies on SGX to rate-limit guesses of a weak PIN. If SGX is broken and Signal's database falls into the wrong hands, encryption keys could be brute-forced pretty quickly (most people have 4-digit PINs).

Its not perfect, but the more people in on a secret the harder it is to keep. Its much harder to have to coerce both intel and signal (even if you hack intel, you would still have to modify signal's servers from what i understand) than just signal.

NSLs are a subpoena. The government can't order you to include a backdoor. Granted, they have other leverage they could use, like export licenses or purchase contracts.

> The government can't order you to include a backdoor.

Right, but it can order you to turn over your private keys, like it did to Lavabit[0]. Intel might instead voluntarily hand over a signed backdoored firmware, targeted at a specific set of CPUs, rather than the keys themselves, which could do more damage if the government lost control of them.

Similarly I don't suppose it would be much harder for the NSA to get access to the physical servers that Signal is running its software on. Perhaps you could say that merely having the access credentials wouldn't be enough information for the NSA to take control of Signal's servers without them noticing, but any cloud provider that wants to do business with the government surely has special backdoors that make this easy, when presented with an NSL.

[0] https://en.wikipedia.org/wiki/Lavabit

What would that accomplish?

Yep. Privacy is a heavily overloaded term; I meant it as a more industry-style "data access management". Some comments in the other thread do talk about non-DRM uses.

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