3 ms·

That's a clear distinction, thanks for bringing it up. For clarity, this lib has 2 hashes: rainbow, and rainstorm. "rainbow" the faster, is not intended to be

That's a clear distinction, thanks for bringing it up. For clarity, this lib has 2 hashes: rainbow, and rainstorm. "rainbow" the faster, is not intended to be crypto secure. "rainstorm" the slower, designed with strength, is, but it has not been analyzed publicly. My intent is that rainstorm is proposed as a cryptohash and eventually is analyzed properly in order to be trusted, and used - or improved! We probably can't remove the "ish" until then. In terms of saying "more secure"? Without formal cryptanalysis it is hard to say, but if you have good statistical properties (as measured by these tests in SMHasher3) it's fair to say you're more secure as a lot of the attacks on (cryptographic) hashes are to do with finding dependencies between input and output ("differentials"). I wouldn't make sweeping recommendations unless a hash was vetted because that's how we end up trusting primitives, through the trust in the collective work of people trying to attack them. Right now we just have the speed results, the SMHasher3 results and the design, and some limited analysis. But more is coming, some people are doing good stuff on GitHub right now. In terms of aptness, to use either of my hashes in rain as a cryptohash without having a deep understanding of potential attacks against it would be rolling the dice, but you could probably trust that at least potential attacks would seem to be difficult given the lack of statistical predictabilities. And they're both fine to use as regular non-cryptographic hashes. Of course I want to recommend people use them, but I couldn't say use them in crypto applications without being irresponsible and I don't want to do that. Also, to be more lawyerly about it, heh, it's provided "as is". I guess the main draw right now is if you want good statistical properties and hashes that can be 64, 128 or 256 (or even 512 in rainstorm) bits wide, and fairly fast for that.

tptacek 2y ago
What does "vetted" mean to you here?
- keepamovin 2y ago
  Just held to the same standards of cryptanalysis that the community decides imbues a cryptohash with trust for use. Pretty standard, and consistent with the rest of the text. What did you think it meant?
  - tptacek 2y ago
    Nothing in particular, but, like, there was just a NIST competition that produced SHA3, and "vetted" Blake2, and this wasn't submitted to it. It's not like there's a test suite to which you can just submit a cryptographic hash to validate it. You actually have to convince a bunch of mathematicians to do studies of your hash, right? I'm not trying to pick on you, it's just that this keeps coming up with constructions like PCG. There's a cryptographic literature, and then a side-hustle of people building stuff like this. We used to have a sci.crypt discourse about it, but now I worry that HN has lost the antibodies.
    - deleted 2y ago
      [deleted]
    - keepamovin 2y ago
      There's 2 hashes here. Rainbow is non-crypto, rainstorm is proposed as a crypto-hash, requiring cryptanalysis. It's not claiming to be validated as a cryptohash by SMHasher3, which tests statistical properties. You need (crypt)analysis to say it's a secure and trusted crypto-hash. This was developed a couple months past the NIST submission deadline for SHA3. Maybe your immune response was wrongly triggered? It happens. But what we really need antibodies against is excessive negativity and vague criticism, combined with attempts to justify the same with "you're not someone who is supposed to do that" gatekeeping. Could some of this be motivated by the fact that you want to do stuff like this yourself, but instead of doing so, or analyzing it, you just criticize it, inappropriately? I don't think you're trying to pick on me, just confused and powered by righteous protective instinct that is better were it more informed and discerning. Reflect some?
      - tptacek 2y ago
        No immune response! Making new things and posting them is an absolute good thing. I'm literally asking, straight up: what's the use case for a hash that is "more secure" than an insecure hash, but "less vetted" than an actual cryptographic hash. That's all.

tptacek 2y ago

What does "vetted" mean to you here?

keepamovin 2y ago
Just held to the same standards of cryptanalysis that the community decides imbues a cryptohash with trust for use. Pretty standard, and consistent with the rest of the text. What did you think it meant?
- tptacek 2y ago
  Nothing in particular, but, like, there was just a NIST competition that produced SHA3, and "vetted" Blake2, and this wasn't submitted to it. It's not like there's a test suite to which you can just submit a cryptographic hash to validate it. You actually have to convince a bunch of mathematicians to do studies of your hash, right? I'm not trying to pick on you, it's just that this keeps coming up with constructions like PCG. There's a cryptographic literature, and then a side-hustle of people building stuff like this. We used to have a sci.crypt discourse about it, but now I worry that HN has lost the antibodies.
  - deleted 2y ago
    [deleted]
  - keepamovin 2y ago
    There's 2 hashes here. Rainbow is non-crypto, rainstorm is proposed as a crypto-hash, requiring cryptanalysis. It's not claiming to be validated as a cryptohash by SMHasher3, which tests statistical properties. You need (crypt)analysis to say it's a secure and trusted crypto-hash. This was developed a couple months past the NIST submission deadline for SHA3. Maybe your immune response was wrongly triggered? It happens. But what we really need antibodies against is excessive negativity and vague criticism, combined with attempts to justify the same with "you're not someone who is supposed to do that" gatekeeping. Could some of this be motivated by the fact that you want to do stuff like this yourself, but instead of doing so, or analyzing it, you just criticize it, inappropriately? I don't think you're trying to pick on me, just confused and powered by righteous protective instinct that is better were it more informed and discerning. Reflect some?
    - tptacek 2y ago
      No immune response! Making new things and posting them is an absolute good thing. I'm literally asking, straight up: what's the use case for a hash that is "more secure" than an insecure hash, but "less vetted" than an actual cryptographic hash. That's all.