just inject this with your favorite JS injection plugin let oldTanh = Math.tanh; Math.tanh = x => oldTanh(x) + Math.random()/10000000;
Multiple anti-bot vendors will detect that replacement and use it as part of their fingerprinting process.
Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS
71–80 of 237 posts
Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS
#72Is 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 don't stop people. They just deter a few people and delay a couple more but a determined person can (likely very easily) break into my house. That is why we need society to call it out that it isn't right (people avoiding buying things they think are stolen, shunning those that do it, etc etc) and laws that step in (it is a crime to break into my house. real resource dedicated to tracking down and stopping people that do it, etc). A similar approach needs to happen here. It should be illegal to track a person like this and people that get hired at a place using the gains of it should shun those companies and society should shun those companies.
Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS
#73Earlier quoted context omitted.
It is when you're doing it like the LLM companies are: at scale, to the degree that you're taking down my site, without my consent by masking your user-agent, for the purpose of stealing data I didn't authorize you to have.
The idiotic "stealing" argument again? At least use "piracy" if you want to be correct... The moment you openly publish information on the Internet, you have already given consent. There are other solutions to bandwidth usage. User-agent discrimination should be illegal. All it does is further the control that Big Tech has, and help authoritarian governments with their control too.
As with anything IP-related, the data is licensed under whatever terms you choose to impose. That’s the extent of the consent you’ve provided.
Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS
#74Earlier quoted context omitted.
I never understood why fixed precision, and integer math isn't more popular. In engineering, we used fixed point all the time, it ran on much simpler hardware and the error is mathematically easy to model. IEEE 754 floats are not only suspect when it comes to theory, but are often outperformed with integers smaller than the mantissa (so less than 24 bits of int can beat a 32 bit float), when it comes to things like l…
I recommend pretty much everyone avoid fixed point and other float alternatives, barring exceptional cases after you've done your own numerical analysis, or you lack floating point hardware (rare these days). Yes, fixed point can use simpler hardware. That's also a completely irrelevant consideration for software. The vast majority of processors are optimized for floats now and some operations (e.g. division) are act…
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Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS
#75Earlier quoted context omitted.
I recommend pretty much everyone avoid fixed point and other float alternatives, barring exceptional cases after you've done your own numerical analysis, or you lack floating point hardware (rare these days). Yes, fixed point can use simpler hardware. That's also a completely irrelevant consideration for software. The vast majority of processors are optimized for floats now and some operations (e.g. division) are act…
fixed-point provides uniform precision, exact integer-scaled arithmetic, is deterministic whereas floating point is more convenient but its not a panacea
As I said, floats can provide results that are no worse than a specified fixed point type. So if you want uniform absolute precision, just round down to the required precision.
Floating point is generally deterministic in practice with a fairly minor amount of effort, the major remaining issue being library rounding. I actually wrote a library that guarantees this for arbitrary code, with some small, obvious caveats like standard library precision. And the conference talks linked above note, the standard library issues are an increasingly solved problem for modern toolchains. The remaining cases are mostly things you won't do in fixed point. Let me know if you're aware of anyone computing erfc in fixed point for determinism though.
I'm not saying there aren't any situations where other systems are justified, but you probably won't know if you fall into any of them without the kind of numerical analysis that most codebases will never receive.
Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS
#76Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS
#77Earlier quoted context omitted.
arith2027.org taken, arith2028.org available.
Well, there's an arbitrage opportunity if I ever saw one
I go to the conference frequently and know the organizing committee. It depends on the year (2025 and 2026 did it, but not 2024). And if someone decides to register arith20xx.org, I doubt the conference would buy it.
Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS
#78Earlier quoted context omitted.
I never understood why fixed precision, and integer math isn't more popular. In engineering, we used fixed point all the time, it ran on much simpler hardware and the error is mathematically easy to model. IEEE 754 floats are not only suspect when it comes to theory, but are often outperformed with integers smaller than the mantissa (so less than 24 bits of int can beat a 32 bit float), when it comes to things like l…
I recommend pretty much everyone avoid fixed point and other float alternatives, barring exceptional cases after you've done your own numerical analysis, or you lack floating point hardware (rare these days). Yes, fixed point can use simpler hardware. That's also a completely irrelevant consideration for software. The vast majority of processors are optimized for floats now and some operations (e.g. division) are act…
I didn't recommend fixed point for simpler HW - I recommended it for better precision (if you know what you are doing). First, a point I didn't make, is that if you have 32 bits of fixed, you get way more precision than with a 32 bit float. But I can think of a pretty common case where a 24 bit int would win against a 32bit float: convolution filters.
If you have a filter whose inputs are supposed to sum up to 1 (which is the most common case), integer computations mean that, even with internal overflows, the end result will be correct. In contrast, with floats, you can lose precision. If you apply said operation 10000x recursively (say, you are 'stepping' a simulation), those errors can add up bigtime.
> Floats are also much easier to get right for your coworkers that aren't numerical analysts.
That one is true, however, when you have people, such as EEs who really care about precision, and know the theory behind it, then floats are often not the obvious choice. It has other advantages, like your calculation running the exact same regardless of CPU and/or compiler, which I'm sure a lot of analysts care about. Afaik finance people don't even use floats for things like account balances, because you can't represent something like 0.1$ exactly.
Fixed point has basically no language support, and is very hard to get right, but sometimes you need to do that.
Do you have any subject matter expertise in quantization errors? Like doing simulations or DSP work? Not trying to be antagonistic, just figure out where you're coming form.
Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS
#79Earlier quoted context omitted.
The idiotic "stealing" argument again? At least use "piracy" if you want to be correct... The moment you openly publish information on the Internet, you have already given consent. There are other solutions to bandwidth usage. User-agent discrimination should be illegal. All it does is further the control that Big Tech has, and help authoritarian governments with their control too.
As with anything IP-related, the data is licensed under whatever terms you choose to impose. That’s the extent of the consent you’ve provided.
Permission to access is not the same as permission to use.
Re: Since Chromium 148, Math.tanh is now fingerprintable to link underlying OS
#80> One tanh call on the right input is a per-OS signature. Claim macOS, return Linux math bits, and you have contradicted your own User-Agent. They (or rather the LLM that wrote this) missed that this is possibly fingerprintable to browser version range, which is slightly more interesting. Most users aren't spoofing their user agent headers to be a different operating system. Most fingerprinting solutions aren't tryin…
You can only assert >148 at the moment, but there are better vectors to strictly assert the version by simply checking the addition of v8/blink on each chromium version (and since ~120 it's the case), so by checking if xxx is present and yyy is not present in js userland or css feature, the inference is 100% for the major version And for the LLM writing, yes, it's written in the article and blog, it's not hidden or p…
It takes less time to write the prompt, you could just publish that?
It's an important topic, and I am glad you wrote about it, but even half a page of notes would have been enough to convey this. It would save me literally skim reading headings just to get past all the fluff.