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Gibson Research Corporation's Ultra-High Entropy Pseudo-Random Number Generator

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Re: Gibson Research Corporation's Ultra-High Entropy Pseudo-Random Number Generator

#31

Post by RobotToaster »

tenebrisalietum wrote: post #11
jrm4 wrote: post #10

Can someone explain to me the value of this? Like, is there value in the "pseudo" that you don't get from a "real" one? Like, I'm thinking of e.g. the Cloudflare lava lamp thing, and like, isn't that better in every way?

Pure software can't actually generate mathematically-provable random numbers unless given purely random data to start with. So pseudo removes total dependency on physical events. Why you don't want to be dependent on physical events: - You never know if physical events are truly random unless you test them. Your physical RNG source may be broken or compromised. - A good strategy is to use multiple physical sources of…

Wasn't there a company that used lava lamps to generate supposedly truly random numbers at one point?

Re: Gibson Research Corporation's Ultra-High Entropy Pseudo-Random Number Generator

#32

Post by easeout »

heleninboodler wrote: post #17
daniel-s wrote: post #6

Earlier quoted context omitted.

What's wrong with Shieldsup? My experience is that it works perfectly fine.

I don't know if there's anything wrong with Sheildsup (other than my recollection of it being a pretty run of the mill tool for reporting open ports), but the guy who makes Shieldsup is, in my opinion, basically a charlatan. He writes loads and loads of technical-sounding blather on his website that is very transparently designed to make him look like an expert on security to people who don't know any better. He's ma…

I feel like what you're describing is just marketing, in the sense of exaggerating the necessity of a product that works but which you really can do without. Or do you mean Gibson's products don't really work?

Re: Gibson Research Corporation's Ultra-High Entropy Pseudo-Random Number Generator

#33

Post by MertsA »

medimikka wrote: post #5

If the maker of ShieldsUp! claims anything, I am deeply, deeply, unconvinced.

Forget "ShieldsUp!" This is the guy who still sells SpinRite for $90 when it hasn't seen an update since 2004. It's old enough to vote at this point and Steve Gibson is always spouting off blatant lies about how it's great for recovering SSDs. He's claimed that it can magically read uncorrectable sectors on modern drives (SATA, not SAS, no SCSI READ LONG here and no ancient IDE drives that still supported READ LONG for ATA) and compare results to figure out what the original data was. He claims that it's data recovery software and that people should run it on a failing hard drive before trying to copy data off of it with a real data recovery program! That piece of garbage doesn't even support writing data to a separate disk, the only thing it can do is write the data the drive was able to read back to the failing drive itself.

The technical documentation claims stuff like that it disables bad sector allocation. That's actually a thing, but if you read the man page for some reputable software like hdparm you'll see a nice little note:

> Control of this feature via the -D option is not supported for most modern drives since ATA-4; thus this command may fail.

ATA-4 was standardized in 1998. It can probably actually disable write caching, but it's not like that's unique to SpinRite in the slightest. It's even trivial to change that on Windows which is otherwise horrible for anything low level involving disks. SpinRite doesn't even use LBA48 addressing so if your drive can't address the full capacity in ye olde CHS then too bad, but SpinRite will try to spin that as a problem with your BIOS, a problem with your SATA controller, etc.

I don't see why anyone respects anything he says given his long history of selling snake oil and other shyster tactics. Even the Wikipedia page for SpinRite looks astroturfed and the talk section has a bunch of responses from an unregistered user that all seem to have a similar tone and be suspiciously supportive of some of SpinRite's dubious claims.

If Steve Gibson told me that the sky was blue I think I'd have to go outside and check.

http://www.hddoracle.com/viewtopic.php?f=181&t=2929

Re: Gibson Research Corporation's Ultra-High Entropy Pseudo-Random Number Generator

#34

Post by dfox »

contravariant wrote: post #4

Something about using a PRNG with a large internal state just to generate an output in a large space of possibilities feels wrong to me. If you have enough entropy to fill a high entropy RNG, why not use all that entropy to generate the output in the first place? Also I'm curious how they generate the latin squares, their claims require a uniform distribution of some kind, which is interesting.

The issue is that you cannot directly pick one of the outputs using the entropy, you have to use some kind of probabilistic algorithm to traverse the state space and find valid output. When the PRNG's cycle is smaller than the output space then the output distribution is obviously non-uniform. This might seem like inconsequential observation with CSPRNG, but depending on how exactly the state traversal works, such constructions can have real output spaces that are several orders of magnitude smaller than cycle of the used RNG. (to the extent that when used with (CS)PRNG with 128b state the output bias is observable from practical amount of outputs)

Re: Gibson Research Corporation's Ultra-High Entropy Pseudo-Random Number Generator

#36

Post by contravariant »

Iwan-Zotow wrote: post #13
contravariant wrote: post #4

Something about using a PRNG with a large internal state just to generate an output in a large space of possibilities feels wrong to me. If you have enough entropy to fill a high entropy RNG, why not use all that entropy to generate the output in the first place? Also I'm curious how they generate the latin squares, their claims require a uniform distribution of some kind, which is interesting.

> If you have enough entropy to fill a high entropy RNG, why not use all that entropy to generate the output in the first place? Problem is the entropy generation rate. PRNG even with large space typically is running at 10 or better Gbit/sec. PCG with 256/64bit could generate decent numbers at 50Gbit/sec

That's not entropy that is data. You fundamentally can't increase entropy, hence why they wanted to use a PRNG with a big internal state so they can put more entropy in.

So if your argument is that you want a big entropy PRNG to get more possible outputs then the generation rate can't be the problem because that's entirely dependent on you being able to generate a big enough seed.

Re: Gibson Research Corporation's Ultra-High Entropy Pseudo-Random Number Generator

#37

Post by tenebrisalietum »

RobotToaster wrote: post #31
tenebrisalietum wrote: post #11

Earlier quoted context omitted.

Pure software can't actually generate mathematically-provable random numbers unless given purely random data to start with. So pseudo removes total dependency on physical events. Why you don't want to be dependent on physical events: - You never know if physical events are truly random unless you test them. Your physical RNG source may be broken or compromised. - A good strategy is to use multiple physical sources of…

Wasn't there a company that used lava lamps to generate supposedly truly random numbers at one point?

I want to say that was Cloudflare.

Re: Gibson Research Corporation's Ultra-High Entropy Pseudo-Random Number Generator

#38

Post by CyberDildonics »

KyeRussell wrote: post #35
CyberDildonics wrote: post #19

Earlier quoted context omitted.

Is this a joke? What does that mean?

Touch grass.

Are you upset because I can't tell if a "DNS speed finer" is a real 'tool'? Wouldn't that just be pinging a list of dns servers?

Re: Gibson Research Corporation's Ultra-High Entropy Pseudo-Random Number Generator

#39

Post by coleca »

icecube123 wrote: post #20
heleninboodler wrote: post #17

Earlier quoted context omitted.

I don't know if there's anything wrong with Sheildsup (other than my recollection of it being a pretty run of the mill tool for reporting open ports), but the guy who makes Shieldsup is, in my opinion, basically a charlatan. He writes loads and loads of technical-sounding blather on his website that is very transparently designed to make him look like an expert on security to people who don't know any better. He's ma…

Thats over 20 years old. Its not worth mentioning in this discussion. He only sells one product, Spin-Rite which actually works pretty well for its purpose, tho it’s becoming less important as we move more towards SSD. It sounds like you’re spreading misinformation just for the hell of it.

I agree. Not sure why all the hate. I’ve used SpinRite to recover some bad drives of mine and friends/family over the years and it’s worked quite well. Had one Windows box that was failing to boot before the login screen, ran SpinRite and it found / fixed some issues. Rebooted and the machine was fine. At least fine enough to copy everything to a new drive and ditch the old one. Haven’t tried it on an SSD though.

Re: Gibson Research Corporation's Ultra-High Entropy Pseudo-Random Number Generator

#40

Post by aappleby »

This is not a good way to generate "secure" random numbers, and the "visits every possible state" is not a good metric.

Computing the cryptographic hash of a 1536-bit counter will have better properties (and less handwaving) than this function.

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