4 ms·

For all the people saying this is security theatre, no, it's one layer of an immense level of paranoia that makes CloudFlare great at what they do. Fun fact, H

For all the people saying this is security theatre, no, it's one layer of an immense level of paranoia that makes CloudFlare great at what they do. Fun fact, HN itself was "hacked" due to bad random once (https://news.ycombinator.com/item?id=639976 https://news.ycombinator.com/item?id=639976).

jgrahamc 3y ago
Random numbers have always worried me. Hence the Lava Lamps etc. at Cloudflare and the fact that I predicted that attack on HN about a month before it happened: https://news.ycombinator.com/item?id=640213 https://news.ycombinator.com/item?id=640213
- ot 3y ago
  But in the case of HN the RNG was seeded by millisecond-granularity timestamps. This was universally considered bad already in 2009 (it would have been even in 1999). The Debian SSL key scandal happened in 2008. It is quite a leap to say "timestamp-based seeds are insecure, let's upgrade to lava lamps".
- WirelessGigabit 3y ago
  I'm reading that post, and while fascinating, I don't understand the entropy calculation. The digit chance is easy: For a single digit to appear one needs 1/3 * 1/10 = 1/30. For a single letter to appear one needs 1/3 * 1/26 = 1/78. But the bits of entropy throw me off. 26 + 26 + 10 = 62, which is 2^5.954. But that is for a uniform distribution. The writer states that it actually is 2^5.826, or 1/~56.7. I don't get how they to that number.
  - lukevalenta 3y ago
    Here's how you can get that entropy using the Shannon entropy equation from https://en.wikipedia.org/wiki/Entropy_(information_theory) https://en.wikipedia.org/wiki/Entropy_(information_theory). Like you said, the probability of any digit appearing is 1/30, and there are 10 digits. The probability of a lower- or upper- case letter appearing is 1/78, and there are 26+26 = 52 letters. Plugging that into the formula for Shannon entropy, we get this: - 10 * (1/30) * log_2(1/30) - 52 * (1/78) * log_2(1/78) =~ 5.826
yellow_lead 3y ago
It is security theater and a marketing stunt. Why not just use a hardware-backed random number generator? For example this has passed NIST SP800-22 and SP800-90B [1]. As far as I can tell, cloudflares DIY lamps/pendulums are not NIST certified. [1] https://www.idquantique.com/random-number-generation/products/quantis-qrng-pcie/ https://www.idquantique.com/random-number-generation/product...
- JoachimS 3y ago
  An NIST certification is a requirement for being secure? Like an RNG with Dual_EC_DRBG - which you could get a certification for. Some would claim that CMVP, FIPS 140-3, Common Criteria stickers on a black box (HSM) is security theater.
- beejiu 3y ago
  > Why not just use a hardware-backed random number generator? They do, don't they? I think the Lavalamps, etc, are just _extra_ entropy. The more entropy you add (even if it's _not_ a certified or perfect random source) only improves the random number generator.
  - InsomniacL 3y ago
    until the fuse for the wall socket blows from having 40 lava lamps plugged in and they all return the same result :D jk.
- josefx 3y ago
  > As far as I can tell, cloudflares DIY lamps/pendulums are not NIST certified. That makes them by definition worse than the OpenSSL version that leaked user keys on request. /s
- brianmcc 3y ago
  I think the term "theatre" implies "is meant to achieve X but fails to", rather than "achieves X in a slightly flamboyant manner". Like all the COVID-prevention theatre: sitting in restaurants and only masking when you visit the toilet. Hand-washing often whilst in unventilated areas with no masks. That's all "COVID theatre" IMO, as it fails to actually prevent the thing ostensibly being tackled. My favourite one FWIW was wiping down the seat padding in the gym where nobody was masked - I mean who came up with that?? A creative hardware source of legit randomness is not the same as security theatre, and arguably has some useful educational aspect - it's certainly a talking point!
jarvist 3y ago
But it is theatre. A single £0.01 Zener diode can generate vastly more guaranteed (by quantum mechanics!) randomness, without all the possibility of failure, entropy leaking etc.
- JoachimS 3y ago
  Please define what you mean with theatre. Yes it is much more cool to look at than a zener diode, but it is still a source of physical entropy. And one could argue that a whole bunch of chaotic pendulums are more resilient to failure than a single diode.
bell-cot 3y ago
Simple argument for "security theatre": Even if Cloudflare happens to use this technology (chaotic pendulums) as an RNG, they'd still put the instance of it that is their on-line RNG somewhere out of sight and seriously secure. The instance that is publicly viewable - and probably has plenty of wanna-be hostiles thinking "how could I use that to..." - would only be connected to their intrusion-detection systems.

jgrahamc 3y ago

Random numbers have always worried me. Hence the Lava Lamps etc. at Cloudflare and the fact that I predicted that attack on HN about a month before it happened: https://news.ycombinator.com/item?id=640213 https://news.ycombinator.com/item?id=640213

ot 3y ago
But in the case of HN the RNG was seeded by millisecond-granularity timestamps. This was universally considered bad already in 2009 (it would have been even in 1999). The Debian SSL key scandal happened in 2008. It is quite a leap to say "timestamp-based seeds are insecure, let's upgrade to lava lamps".
WirelessGigabit 3y ago
I'm reading that post, and while fascinating, I don't understand the entropy calculation. The digit chance is easy: For a single digit to appear one needs 1/3 * 1/10 = 1/30. For a single letter to appear one needs 1/3 * 1/26 = 1/78. But the bits of entropy throw me off. 26 + 26 + 10 = 62, which is 2^5.954. But that is for a uniform distribution. The writer states that it actually is 2^5.826, or 1/~56.7. I don't get how they to that number.
- lukevalenta 3y ago
  Here's how you can get that entropy using the Shannon entropy equation from https://en.wikipedia.org/wiki/Entropy_(information_theory) https://en.wikipedia.org/wiki/Entropy_(information_theory). Like you said, the probability of any digit appearing is 1/30, and there are 10 digits. The probability of a lower- or upper- case letter appearing is 1/78, and there are 26+26 = 52 letters. Plugging that into the formula for Shannon entropy, we get this: - 10 * (1/30) * log_2(1/30) - 52 * (1/78) * log_2(1/78) =~ 5.826

yellow_lead 3y ago

It is security theater and a marketing stunt. Why not just use a hardware-backed random number generator? For example this has passed NIST SP800-22 and SP800-90B [1]. As far as I can tell, cloudflares DIY lamps/pendulums are not NIST certified. [1] https://www.idquantique.com/random-number-generation/products/quantis-qrng-pcie/ https://www.idquantique.com/random-number-generation/product...

JoachimS 3y ago
An NIST certification is a requirement for being secure? Like an RNG with Dual_EC_DRBG - which you could get a certification for. Some would claim that CMVP, FIPS 140-3, Common Criteria stickers on a black box (HSM) is security theater.
beejiu 3y ago
> Why not just use a hardware-backed random number generator? They do, don't they? I think the Lavalamps, etc, are just _extra_ entropy. The more entropy you add (even if it's _not_ a certified or perfect random source) only improves the random number generator.
- InsomniacL 3y ago
  until the fuse for the wall socket blows from having 40 lava lamps plugged in and they all return the same result :D jk.
josefx 3y ago
> As far as I can tell, cloudflares DIY lamps/pendulums are not NIST certified. That makes them by definition worse than the OpenSSL version that leaked user keys on request. /s
brianmcc 3y ago
I think the term "theatre" implies "is meant to achieve X but fails to", rather than "achieves X in a slightly flamboyant manner". Like all the COVID-prevention theatre: sitting in restaurants and only masking when you visit the toilet. Hand-washing often whilst in unventilated areas with no masks. That's all "COVID theatre" IMO, as it fails to actually prevent the thing ostensibly being tackled. My favourite one FWIW was wiping down the seat padding in the gym where nobody was masked - I mean who came up with that?? A creative hardware source of legit randomness is not the same as security theatre, and arguably has some useful educational aspect - it's certainly a talking point!

jarvist 3y ago

But it is theatre. A single £0.01 Zener diode can generate vastly more guaranteed (by quantum mechanics!) randomness, without all the possibility of failure, entropy leaking etc.

JoachimS 3y ago
Please define what you mean with theatre. Yes it is much more cool to look at than a zener diode, but it is still a source of physical entropy. And one could argue that a whole bunch of chaotic pendulums are more resilient to failure than a single diode.

bell-cot 3y ago

Simple argument for "security theatre": Even if Cloudflare happens to use this technology (chaotic pendulums) as an RNG, they'd still put the instance of it that is their on-line RNG somewhere out of sight and seriously secure. The instance that is publicly viewable - and probably has plenty of wanna-be hostiles thinking "how could I use that to..." - would only be connected to their intrusion-detection systems.