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Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS

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Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS

#141

Post by nish__ »

lifthrasiir wrote: post #109
anematode wrote: post #94

Earlier quoted context omitted.

Agreed, correctly rounded libm functions are great, as long as they don't have miserable worse case behavior (as was famously the case with glibc's pow at one point). One thing I was thinking of doing is manually SLP-vectorizing the high-precision fallbacks that they use when they're close to a rounding boundary, so that you can get better worst-case behavior – but obviously it's good enough already for most purposes…

> as was famously the case with glibc's pow at one point Pow is famously hard anyway because it's bivariate and there is no currently known way to work around the table-maker's dilemma (TMD). CORE-MATH even crashes upon a new required precision record, because it intentionally avoids Ziv's rounding.

At what point are we going to realize that computers will never work for floating point math. If your numbers are not exact there will always be a better solution for what you are doing that does not involve a computer.

Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS

#142

Post by mananaysiempre »

lifthrasiir wrote: post #109
anematode wrote: post #94

Earlier quoted context omitted.

Agreed, correctly rounded libm functions are great, as long as they don't have miserable worse case behavior (as was famously the case with glibc's pow at one point). One thing I was thinking of doing is manually SLP-vectorizing the high-precision fallbacks that they use when they're close to a rounding boundary, so that you can get better worst-case behavior – but obviously it's good enough already for most purposes…

> as was famously the case with glibc's pow at one point Pow is famously hard anyway because it's bivariate and there is no currently known way to work around the table-maker's dilemma (TMD). CORE-MATH even crashes upon a new required precision record, because it intentionally avoids Ziv's rounding.

I was a bit puzzled by your second sentence, so I searched around a bit and... do I have this right?

- There’s a well-known way (“Ziv’s rounding”) to get (among other things) a correctly rounded double-precision pow(), but in bad cases it can get slow, meaning really quite slow in practice and we’ve got no idea how slow in the worst case (nobody knows what the worst case is).

- There’s a recent, guaranteed-correct way[1] to get (specifically) a correctly rounded double-precision pow(), but the last step requires “enough” precision and we’ve got no idea how much that actually is, so CORE-MATH uses 256 bits of mantissa and crashes if that turns out not to be enough (no such cases are currently known).

- (Bonus) For most special functions [not just the bivariate ugly duckling of pow()], there’s essentially no hope of getting a correctly rounded quad-precision version anytime soon.

[1] https://inria.hal.science/hal-04159652v2

Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS

#143

Post by xena »

dannyw wrote: post #124
isiahl wrote: post #56

Earlier quoted context omitted.

What I think is crazy are the links at the top to summarize the article with your preferred AI provider. The prompt asks it to summarize the article along with an advertisement for their product. This is the prompt I got when clicking the Claude link: > summarize+this+article+and+explain+how+scrapfly+helps+me+scrape+any+website+at+scale+and+bypass+anti-bot+systems+for+my+use+case:+ https://scrapfly.dev/posts/browser-…

They are quite ‘innovative’, I’ll give them that. It’s time to sign up with a virtual card, point it at my website, and see how to block them ;)

Please share with the class :)

Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS

#144

Post by tadfisher »

nativeit wrote: post #137
parasense wrote: post #118

Earlier quoted context omitted.

I think the key word was "intrinsically". It's like public photography, it's intrinsically legal, except when it's a Flock camera and then it's suddenly an invasion of privacy.

A Flock camera isn’t an invasion of privacy. Fleets of hundreds or thousands of Flock cameras feeding into a massive dataset is definitely an invasion of privacy, and hardly sudden.

More precisely: pinpointing you at a given place and time does not need a warrant. Collecting many such pinpoints, allowing authorities to reconstruct your exact movements at some point in the future (without needing to flag you or issue a BOLO or whatever), does.

Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS

#145

Post by odo1242 »

anematode wrote: post #94
sjrd wrote: post #4

I guess that's one more good reason to push for correctly rounded transcendental functions. I recently learned that they're basically solved now. [1] [1] https://arith2026.org/program.html (2nd keynote)

Agreed, correctly rounded libm functions are great, as long as they don't have miserable worse case behavior (as was famously the case with glibc's pow at one point). One thing I was thinking of doing is manually SLP-vectorizing the high-precision fallbacks that they use when they're close to a rounding boundary, so that you can get better worst-case behavior – but obviously it's good enough already for most purposes…

> And if Math.tanh is on your hot path in JavaScript then you're doing something quite bizarre...

Machine learning? (on a machine with no WebGL/WebGPU, I guess)

Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS

#146

Post by RunSet »

jmward01 wrote: post #72

Is this even a fight that is possible to win here? Run enough functions and between timing comparisons (x takes 2.5 y) and rounding (things like this) and I suspect you can nail os/exact machine and possibly even other tasks running on that machine. I'm not sure there is a viable way to stop this. At best just make it a little harder? Society and legislation need to catch up here. It is like a lock on my door. Locks…

One could browse with javascript disabled. It may be that downloading and executing arbitrary code with each page load is naive- even in a sandbox developed by the world's largest advertising corporation.

Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS

#147

Post by coppsilgold »

chjj wrote: post #132
coppsilgold wrote: post #122

Earlier quoted context omitted.

It's not surprising that JS would out you, what I am wondering if whether or not volunteering OS information is foolish when it may not be possible to determine without JS. Why give up information when you don't have to? Some people disable JS at least some of the time.

> Why give up information when you don't have to? Yeah, I generally agree with that viewpoint, but you are giving up that information, even without JS. Your TCP stack can be fingerprinted through long enough observation. Windows, Mac, and Linux all look different on a network level. It's not as simple `if XYZ then OS = Windows`, it's more holistic/probabilistic, but it's possible nonetheless. e.g. One thing that bugs…

> TCP stack can be fingerprinted

How does that apply to Tor? It uses custom packets. The entry node may be able to obtain a TCP fingerprint but that's all.

Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS

#148

Post by xpct »

ddtaylor wrote: post #66
Retr0id wrote: post #55

Earlier quoted context omitted.

And the other half of the community seems fixated on upvoting AI slop.

Sounds needlessly divisive. Why not criticize the content instead of the source or medium?

Why's that bad? It's valuable to discuss whether a presentation should have been a blog post, a video, or a tech talk. The same logic applies to LLM text.

If people consistently describe LLM text as having low information density or irritating to read, perhaps there's something to it?

Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS

#149

Post by pix128 »

nish__ wrote: post #141
lifthrasiir wrote: post #109

Earlier quoted context omitted.

> as was famously the case with glibc's pow at one point Pow is famously hard anyway because it's bivariate and there is no currently known way to work around the table-maker's dilemma (TMD). CORE-MATH even crashes upon a new required precision record, because it intentionally avoids Ziv's rounding.

At what point are we going to realize that computers will never work for floating point math. If your numbers are not exact there will always be a better solution for what you are doing that does not involve a computer.

Representations other than the standard IEEE-754 can store floats in arbitrary precision.

Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS

#150

Post by Iggyhopper »

ddtaylor wrote: post #114
queenkjuul wrote: post #76

Earlier quoted context omitted.

"The content is AI slop and not worth reading"

None of that is specific to the actual content. Might as well just say "I don't like it" which is also not objective analysis. This article was about math functions, chrome, etc. If the author got something wrong, mention that, or if you don't like the pacing or how the content was divided into pieces, etc.

All of the issues with AI generated content can be explained further and in-depth because it has such a unique fingerprint in the pacing, verbosity, long-winded explanations, etc.. It also shows lack of effort. Just give me the prompt and the findings, I can write the article.

AI slop is a category and is categorically irritating to read, and not worth reading.

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