31–40 of 62 posts
Nothing is random enough for an arbitrary audience. There's always the possibility that some alien spaceship will land and some creature will emerge, take a glance at your RNG, and say: "next one's 6598489811, try it" and they'll be right. We can only say that something is random enough given a certain audience's beliefs about what kind of predictions are possible. If it takes lava lamps to convince that audience, we…
https://blog.cloudflare.com/lavarand-in-production-the-nitty...
They even mention it's origins in Lavarand (and LavaRand) the former which has an actual patent: https://patents.google.com/patent/US5732138A/en
Yes there's a bit of theater here, and they admit to using the sensor noise as well, it's also not their only source of physical entropy. While you could do just as much with less interesting sources the wall of lava lamps is a perfectly cromulent source of randomness, also is kinda fun.
They don't actually do anything, but I think it's hard to tell a story where they make things worse, given that Cloudflare is a cryptographically competent org. It's just getting mixed into the already-secure conventional CSPRNG they're using (almost certainly: just the Linux kernel RNG).
They don't actually do anything, but I think it's hard to tell a story where they make things worse, given that Cloudflare is a cryptographically competent org. It's just getting mixed into the already-secure conventional CSPRNG they're using (almost certainly: just the Linux kernel RNG).
The lava lamps aren't being used as a CSPRNG, rather they constitute part of the seed for the CSPRNG.
Earlier quoted context omitted.
> I think it's hard to tell a story where they make things worse [...] mixed into the [...] CSPRNG I think it's easy to tell a story where it's slightly worse. I mean, for any budget of storage bits and CPU cycles, any "inferior" random data necessarily pushes out "better" stuff.
It's all hashed together. The whole LRNG design assumes most of its inputs are structured or poorly randomized.
Imagine that tomorrow some reaction caused all those lava-lamps to cloud over into pure, constant, and uniform milky white. What effect would that have? It would make the system at least somewhat less secure, no matter how many hash functions were already scattered around the place.
Lotta speculation about it's value but seems cloudflare does legitimately use this source. https://blog.cloudflare.com/lavarand-in-production-the-nitty... They even mention it's origins in Lavarand (and LavaRand) the former which has an actual patent: https://patents.google.com/patent/US5732138A/en Yes there's a bit of theater here, and they admit to using the sensor noise as well, it's also not their only source of…
Earlier quoted context omitted.
It's all hashed together. The whole LRNG design assumes most of its inputs are structured or poorly randomized.
I'm not sure what you mean, deterministic hashing does not create more entropy than you started with. Lower-quality inputs means lower-quality results. You only want to use low-quality sources if the good stuff is too scarce or expensive. Imagine that tomorrow some reaction caused all those lava-lamps to cloud over into pure, constant, and uniform milky white. What effect would that have? It would make the system at…
Earlier quoted context omitted.
I'm not sure what you mean, deterministic hashing does not create more entropy than you started with. Lower-quality inputs means lower-quality results. You only want to use low-quality sources if the good stuff is too scarce or expensive. Imagine that tomorrow some reaction caused all those lava-lamps to cloud over into pure, constant, and uniform milky white. What effect would that have? It would make the system at…
In the immortal words of a cryptographic folk hero, if H(x, y) produces a good random number, H(x, y, z) will produce a number at least as good.
In other words, these are the two functions that should be compared:
h(content, very_random_bits(32))
h(content, very_random_bits(16) + slightly_random_bits(16))