Y’all motherfuckers need the compose key.
Y’all motherfuckers need the compose key.
Yes, it’s forbidden fruit.
It basically varies from chip to chip, and program to program.
Speculative execution is when a program hits some kind of branch (like an if-then statement) and the CPU just goes ahead and calculates as if it’s true, and progresses down that line until it learns “oh wait it was false, just scrub all that work I did so far down this branch.” So it really depends on what that specific chip was doing in that moment, for that specific program.
It’s a very real performance boost for normal operations, but for cryptographic operations you want every function to perform in exactly the same amount of time, so that something outside that program can’t see how long it took and infer secret information.
These timing/side channel attacks generally work like this: imagine you have a program that tests if variable X is a prime number, by testing if every number smaller than X can divide evenly, from 2 on to X. Well, the bigger X is, the longer that particular function will take. So if the function takes a really long time, you’ve got a pretty good idea of what X is. So if you have a separate program that isn’t allowed to read the value of X, but can watch another program operate on X, you might be able to learn bits of information about X.
Patches for these vulnerabilities changes the software to make those programs/function in fixed time, but then you lose all the efficiency gains of being able to finish faster, when you slow the program down to the weakest link, so to speak.
This particular class of vulnerabilities, where modern processors try to predict what operations might come next and perform them before they’re actually needed, has been found in basically all modern CPUs/GPUs. Spectre/Meldown, Downfall, Retbleed, etc., are all a class of hardware vulnerabilities that can leak crypographic secrets. Patching them generally slows down performance considerably, because the actual hardware vulnerability can’t be fixed directly.
It’s not even the first one for the Apple M-series chips. PACMAN was a vulnerability in M1 chips.
Researchers will almost certainly continue to find these, in all major vendors’ CPUs.
Can’t fix the vulnerability, but can mitigate by preventing other code from exploiting the vulnerability in a useful way.
If you’re looking in the library for books that are at least 100 years old, you’re generally only going to see the ones that people thought were worth preserving for 100 years.
If you’re training your image generation model with stock photographs, you’re generally only going to be giving it images of people who are literally models. Not all models are beautiful, but they’re probably more beautiful on average than the general population.
Well it’s obvious that Musk wants X to be a bank, so this isn’t unexpected.
For what it’s worth, that particular format war, the format backed by more porn studios (HD-DVD) actually lost to the one with less porn backing (Blu-ray). Personally I think that the PS3 tipped things over the edge.