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Re:Google abandons work to move Assistant smart speakers to ... by pclmulqdq on Tuesday July 25, 2023 @10:38PM (#36872489)
Security people very often underestimate the performance impact of encryption (especially on embedded devices), so the former would not be surprising to me. Without acceleration, AES hurts and is incredibly hard to implement without opening up side-channel attacks. SHA is also very slow without acceleration. Both have simple, more modern alternatives that are a lot faster on embedded (ChaCha and Blake2 respectively).

Of course, they are also often unwilling to compromise on their chosen security practices to adapt to the situation, even if that just means switching to lightweight/embedded-friendly cryptography algorithms with similar security levels.

Re:Google abandons work to move Assistant smart speakers to ... by eyegor on Wednesday July 26, 2023 @12:42AM (#36873186)
Fyi, blake3 was released in 2019 and should probably be used over blake2 unless you have some strong reason not to. It's basically a reimplementation of blake2 with performance tweaks.

https://github.com/BLAKE3-team/BLAKE3

If you need a non cryptographic hash, the xxhash family is crazy fast.

https://github.com/Cyan4973/xxHash

Re:Google abandons work to move Assistant smart speakers to ... by im3w1l on Wednesday July 26, 2023 @07:55AM (#36876202)
What about "my library of choice doesn't support blake3 yet"? Is the improvement large enough to go out of your way to upgrade?
Re:Google abandons work to move Assistant smart speakers to ... by pclmulqdq on Wednesday July 26, 2023 @01:25PM (#36881400)
It's Google. Their library of choice supports whatever the hell they want.
Re:Google abandons work to move Assistant smart speakers to ... by im3w1l on Wednesday July 26, 2023 @04:37PM (#36884614)
I meant for other people
Re:Google abandons work to move Assistant smart speakers to ... by necrophcodr on Wednesday July 26, 2023 @11:21AM (#36879247)
That reason could well be that the hardware doesn't support it, or that it is too slow.

With that said, if the hardware cannot what is required, and SoM chips are required, then... Maybe better hardware should be used.

Re:Google abandons work to move Assistant smart speakers to ... by KirillPanov on Wednesday July 26, 2023 @04:28AM (#36874649)
Cannot upvote enough.

This decision reeks of DJB-hating. A lot of NIST types really hate the fact that there are now first-class hashes and symmetric ciphers that perform well without crypto-specific accelerators. This makes bugdooring a lot harder. And then the same guy went and published a curve (Ed25519) whose implementation is nearly impossible to fuck up in ways that leak your secrets.

Lesson to be learned: don't piss off supergenius mathematicians.

Re:Google abandons work to move Assistant smart speakers to ... by jart on Wednesday July 26, 2023 @06:04AM (#36875227)
Blake vs. Nist is irrelevant to the performance debate, because no matter what you do, they're both going to go approximately the same speed. The debate is why hardcore 256+ bit crypto is needed at all by the operating system primitives on a simple device living in my home, when doing that goes literally 30x slower than using something like crc32 or xxxhash. Not to mention that if you're pushing for hard crypto merkle tree stuff, you'd be a fool to do it without things like ecc ram too. Since cosmic rays will blow up your data structures. So you're not just making embedded go slow. You're making it less reliable too. Just to wield ironclad remote control of people's personal possessions.
Re:Google abandons work to move Assistant smart speakers to ... by petertodd on Wednesday July 26, 2023 @06:17AM (#36875314)
> Not to mention that if you're pushing for hard crypto merkle tree stuff, you'd be a fool to do it without things like ecc ram too. Since cosmic rays will blow up your data structures. So you're not just making embedded go slow. You're making it less reliable too. Just to wield ironclad remote control of people's personal possessions.

Can you give me an example of how a bit-flip would blow up a cryptographic merkle tree, but not blow up a non-cryptographic file system?

Re:Google abandons work to move Assistant smart speakers to ... by pravus on Wednesday July 26, 2023 @06:41AM (#36875473)
> Can you give me an example of how a bit-flip would blow up a cryptographic merkle tree, but not blow up a non-cryptographic file system?

Any bit changes anywhere in the merkle tree immediately destroy its ability to self-verify because the integrity is ruined. Basically the entire tree is dead because you can't add new nodes.

Non-cryptographic file systems? A bit-flip changes 1-bit in an isolated place. That one place is ruined but can be easily recovered with checksums or strategies like RAID parity. Detection is harder, though.

Either can be recovered at the block level, though.

I use merkel trees as a solution for a project at work and it has brittleness issues related to data integrity and we have to solution specifically around it.

Re:Google abandons work to move Assistant smart speakers to ... by jart on Wednesday July 26, 2023 @06:40AM (#36875466)
* * *
Re:Google abandons work to move Assistant smart speakers to ... by londons_explore on Wednesday July 26, 2023 @06:58AM (#36875620)
Turns out most bit flips in non-crypto systems simply have no effect.

A bitflip in an error handling path of a binary, where that error never happens - no user impact.

A bitflip in a bitmap image buffer - user doesn't notice one miscoloured pixel for 1 frame in an animation.

A bitflip in a config datastructure changing 0x00000001 to 0x00400001 - no impact because the whole number is treated as boolean anyway.

Re:Google abandons work to move Assistant smart speakers to ... by jacquesm on Wednesday July 26, 2023 @07:45AM (#36876090)
A bitflip in a config datastructure changing 0x00000001 to 0x00000000 - whatever impact you want to imagine.
Re:Google abandons work to move Assistant smart speakers to ... by pclmulqdq on Wednesday July 26, 2023 @11:42AM (#36879633)
1 in 32 is good odds to me.
Re:Google abandons work to move Assistant smart speakers to ... by jacquesm on Wednesday July 26, 2023 @04:00PM (#36884040)

   if (launch) {
     do_launch();
   }
   else {
     printf("this is just a test...\n");
   }
Re:Google abandons work to move Assistant smart speakers to ... by jefftk on Wednesday July 26, 2023 @07:26AM (#36875900)
> The debate is why hardcore 256+ bit crypto is needed at all by the operating system primitives on a simple device living in my home

A device with a microphone and network connection? You don't think people would be excited to hack that?

Re:Google abandons work to move Assistant smart speakers to ... by jart on Wednesday July 26, 2023 @07:42AM (#36876054)
Someone who feels comfortable letting a tech company control a microphone in their home (and by proxy all the agencies that company is obligated by law to serve) probably isn't too concerned about the local neighborhood prankster getting in on the action too. I think the great fear they have is that someone will come along and install a daemon on that speaker which charges them rent.
Re:Google abandons work to move Assistant smart speakers to ... by jacquesm on Wednesday July 26, 2023 @07:44AM (#36876081)
I would be just as concerned - if not more - about Google having access to such a device as I am about some random hacker.
Re:Google abandons work to move Assistant smart speakers to ... by pclmulqdq on Wednesday July 26, 2023 @07:49AM (#36876145)
Is the extra 100 bits of security on your cryptography standard what's actually going to stop them?

In reality, most hacks are stopped by stupid stuff, like closing down ports and proper key management hygiene, not by using completely-brute-force-proof encryption standards. I'll make you a deal: do everything else on that compute-limited embedded device to a practically-uncrackable standard, then you can upgrade to 256 bit crypto. Some devices get there, but no consumer electronics.

Encrypting the filesystem on that specific device is also completely irrelevant to my security as a user - it has more to do with Google protecting itself from copies and users being able to add features.

Re:Google abandons work to move Assistant smart speakers to ... by jart on Wednesday July 26, 2023 @08:10AM (#36876343)
Third parties who want to exploit the relationship between Google and its users are certainly not users. I don't think it's productive to question their intentions. The better question to be asking here is how or why we allowed our homes to become yet another front in the war between Google and its adversaries. Their business model doesn't jive with third amendment culture. I reject any world in which there's a legitimate need for military grade encryption in my home. That is not the future I'm rooting for.
Re:Google abandons work to move Assistant smart speakers to ... by mobilio on Wednesday July 26, 2023 @04:29AM (#36874656)
Even Raspberry Pi (all of them!) doesn't have AES accelerated instructions.
Re:Google abandons work to move Assistant smart speakers to ... by civilitty on Wednesday July 26, 2023 @07:16AM (#36875793)
That’s not a big deal on a multi-core 1ghz processor. Much bigger deal on a single core 200mhz microcontroller that doesn’t have branch prediction or any of those fun optimizations.
Re:Google abandons work to move Assistant smart speakers to ... by Symmetry on Wednesday July 26, 2023 @08:16AM (#36876392)
I know you're pointing at the general class of hardware performance enhancements including branch prediction, hardware prefetching, superscaler execution, pipelining, etc. But out of all of them, if you get a speedup for any advanced branch prediction beyond just always assuming branches are taken then I'd be very worried your cryptographic algorithm is broken.