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As a layman how does this physical random generation help with security. Can any hacker ever chase any random enough number generated by some algorithm? To me i

As a layman how does this physical random generation help with security. Can any hacker ever chase any random enough number generated by some algorithm? To me it looks like if there was 0.001 percent chance of guessing a random this technique just reduces that chance in theory. A long enough password is already considered secure, how does this thing make it any more secure in practice?

yyykk 3y ago
It doesn't, it's really just an art piece. The same could be achieved electronically with a simple circuit inside their servers, but it wouldn't look quite as good.
- xLaszlo 3y ago
  Until it turns out that the NSA was involved writing said RNG and explicitly weekend it with a backdoor...
  - rcxdude 3y ago
    These circuits are really simple. Unless the NSA has backdoored solid-state physics it's no greater a risk than this approach. (The NSA very well could backdoor the camera you point at these pendulums).
    - xLaszlo 3y ago
      Hmm, I had to check this and came across this thread on Reddit. NIST has a standard for it, but the exact point is that _that_ can be influenced by them. Also, somewhere in the thread, they mention that it is probably too hard to verify how it is actually implemented in the hardware. https://www.reddit.com/r/crypto/comments/klcx4p/is_true_random_number_generation_in_modern/ https://www.reddit.com/r/crypto/comments/klcx4p/is_true_rand... I guess in security only the paranoid prevails... Or it is indeed just a cool gimmick...
  - deleted 3y ago
    [deleted]
Legend2440 3y ago
It's really just for the purpose of looking cool. Modern CPUs include hardware random number generators that work just fine.
- hbossy 3y ago
  According to their producers. Do you trust them?
  - Legend2440 3y ago
    If your can't trust your CPU, you are screwed - no matter what entropy source you use.
- JoachimS 3y ago
  Things can be more than one thing. Of course it is a PR piece. But it is also a source of entropy that is hard to manipulate (if we ignore the cameras, image generation etc). And it is a good source, initiator for discussions about entropy, random numbers and why we need them to secure things. This thread on HN shows that it is so. And for 'normal' people probably even more. I'm sure they have a lot of non-geeky visitors that look at the installation, read the sign and start asking questions. And if it was me, starting to jump in front of the installation, waving my arms - to provide my bit of entropy to the pool.
acatton 3y ago
Random numbers are used to generate your TLS certificate key or your SSH key. If one can predict how a TLS or SSH key was generated they could impersonate the key holder. Here is an explanation of what was possible when a Debian packager mistakenly introduced a patch which reduced the SSL certificate keyspace in 2008: https://jblevins.org/log/ssh-vulnkey https://jblevins.org/log/ssh-vulnkey The possibilities of keys which were generated by this random number generator was so small, that a brute-force attack on keys was feasible. That being said, for years, random number generators have been using random signals coming to your computer (key strokes, network packets, ...) and feeding them into a sponge function. You don't need lava lamps or pendulums to generate random numbers, it's just for the press. https://www.2uo.de/myths-about-urandom/ https://www.2uo.de/myths-about-urandom/
- tetha 3y ago
  Speedrunners abuse this in a fun way on older consoles, RNG manipulation [1]. For example the SNES had no actual source of random numbers, so games had to use the inputs as the most unpredictable random source. However, if you do that, people figure out how you can scroll through a menu to force an item to drop or an attack to become great[2] If implemented in full tool assisted speedruns, this can become entirely ridiculous. That rare thing you need to grind hours to find? nope. just press these 18 buttons starting at the right frame and it'll drop first try. 1: https://www.youtube.com/watch?v=MNQaZFwu57E https://www.youtube.com/watch?v=MNQaZFwu57E 2: https://www.youtube.com/watch?v=-sfE8qLCnQY https://www.youtube.com/watch?v=-sfE8qLCnQY
  - tialaramex 3y ago
    Nintendo's relatively modern Mario Maker 2 even deliberately chooses not to have real randomness. "Random" MM2 courses such as "Carlsino" actually rely on subtle differences in player inputs, if you could ensure you don't deviate from a certain series of button presses and timings then the "random" elements would always turn out the same.
    - tetha 3y ago
      Aye. It is a very interesting question if you need or even want full randomness in a game. If you have something that's geared towards speed running, fast execution and mastering, being deterministic is actually a good thing. Otherwise, the player has to re-roll a hundred times to get the "good seed" to get a good run - that's very frustrating. Look at some of the kings quest speedruns for this kinda frustration. Or in a similar direction - tetris with a true random piece selection can result in very frustrating and unwinnable piece sequences (which bastard tetris is dialing to 12). Instead, quite a few modern implementations choose some set of tetrimonios and fill a bag with 3-5 repetitions of this set and choose from that. This limits the possibility and length of possibly frustrating pieces.
defrost 3y ago
A single random password simply isn't enough - Cloudflare deals in millions (actually many many more) of secure handshakes per second. Each has to be secure with a unique unpredictable element. One way (of many) is to use complex PRNG's - Psuedo Random Number Generators, but these can (theorectically) be sequence guessed and then are predictable (or least have a greatly reduced "guess space"). A hybrid way is to regularly reseed a PRNG with a "truly random" starting point, milk that for a few hundred values, and then kick it again with a new random seed. These particular pendulums have "simple" mechanics that are similar to the dynamic systems represented by Lorenz's Butterfly [1] (not exactly but with similar properties) and thus move in chaotic unpredicable ways (such as the timing between the last crossbar changing directions) - these can be "driven" (the base rocked | vibrated) by a small motor) so they continuusly move and yet the path through phase space is still unpredictable. So, without knowing for certain whether this is what Cloudflare is doing here, that is one way in which many many truly random numbers can be generated to feed into secure handshakes; using unpredictable seeds to feed into twisted PRNGs. [1] https://en.wikipedia.org/wiki/Lorenz_system https://en.wikipedia.org/wiki/Lorenz_system
- zelphirkalt 3y ago
  Seemingly chaotic does not equal random. But unless someone figures out a way to make the chaotic seem no longer chaotic, it will be good enough for our purposes.
GuB-42 3y ago
There are many algorithms where instead of transferring data using a computationally expensive (usually public key, like RSA) algorithm, the data is encrypted with a much faster (usually symmetrical, like AES) algorithm using a random key and then the key is transferred using the expensive algorithm. If you can guess how the random key is generated, then you can decrypt the message without breaking either encryption algorithm. That's why it is important to have really unpredictable random data, and physical randomness is the best for that. In practice, that wall of pendulums is unlikely to make a difference compared to the more mundane techniques used in most computers these days, that rely on some CSPRNG combined with various hard to predict system events (ex: interrupt timing), but it looks way cooler.
moritonal 3y ago
Fun fact, Hackernews itself was "hacked" by a user doing exactly this. A user realised they could successfully guess the key-space the server used to encrypt it's user cookies. Had it had a greater source of random it wouldn't have been possible. https://news.ycombinator.com/item?id=639976 https://news.ycombinator.com/item?id=639976
- jgrahamc 3y ago
  Amusingly, I had pointed out that HN was vulnerable to such an attack about a month before that user did it. And I was also involved into setting up Cloudflare's Lava Lamps. https://news.ycombinator.com/item?id=640213 https://news.ycombinator.com/item?id=640213
astura 3y ago
Here's an (old) example of poor random number generation leading to an exploit - https://www.developer.com/guides/how-we-learned-to-cheat-at-online-poker-a-study-in-software-security/ https://www.developer.com/guides/how-we-learned-to-cheat-at-...

yyykk 3y ago

It doesn't, it's really just an art piece. The same could be achieved electronically with a simple circuit inside their servers, but it wouldn't look quite as good.

xLaszlo 3y ago
Until it turns out that the NSA was involved writing said RNG and explicitly weekend it with a backdoor...
- rcxdude 3y ago
  These circuits are really simple. Unless the NSA has backdoored solid-state physics it's no greater a risk than this approach. (The NSA very well could backdoor the camera you point at these pendulums).
  - xLaszlo 3y ago
    Hmm, I had to check this and came across this thread on Reddit. NIST has a standard for it, but the exact point is that _that_ can be influenced by them. Also, somewhere in the thread, they mention that it is probably too hard to verify how it is actually implemented in the hardware. https://www.reddit.com/r/crypto/comments/klcx4p/is_true_random_number_generation_in_modern/ https://www.reddit.com/r/crypto/comments/klcx4p/is_true_rand... I guess in security only the paranoid prevails... Or it is indeed just a cool gimmick...
- deleted 3y ago
  [deleted]

Legend2440 3y ago

It's really just for the purpose of looking cool. Modern CPUs include hardware random number generators that work just fine.

hbossy 3y ago
According to their producers. Do you trust them?
- Legend2440 3y ago
  If your can't trust your CPU, you are screwed - no matter what entropy source you use.
JoachimS 3y ago
Things can be more than one thing. Of course it is a PR piece. But it is also a source of entropy that is hard to manipulate (if we ignore the cameras, image generation etc). And it is a good source, initiator for discussions about entropy, random numbers and why we need them to secure things. This thread on HN shows that it is so. And for 'normal' people probably even more. I'm sure they have a lot of non-geeky visitors that look at the installation, read the sign and start asking questions. And if it was me, starting to jump in front of the installation, waving my arms - to provide my bit of entropy to the pool.

acatton 3y ago

Random numbers are used to generate your TLS certificate key or your SSH key. If one can predict how a TLS or SSH key was generated they could impersonate the key holder. Here is an explanation of what was possible when a Debian packager mistakenly introduced a patch which reduced the SSL certificate keyspace in 2008: https://jblevins.org/log/ssh-vulnkey https://jblevins.org/log/ssh-vulnkey The possibilities of keys which were generated by this random number generator was so small, that a brute-force attack on keys was feasible. That being said, for years, random number generators have been using random signals coming to your computer (key strokes, network packets, ...) and feeding them into a sponge function. You don't need lava lamps or pendulums to generate random numbers, it's just for the press. https://www.2uo.de/myths-about-urandom/ https://www.2uo.de/myths-about-urandom/

tetha 3y ago
Speedrunners abuse this in a fun way on older consoles, RNG manipulation [1]. For example the SNES had no actual source of random numbers, so games had to use the inputs as the most unpredictable random source. However, if you do that, people figure out how you can scroll through a menu to force an item to drop or an attack to become great[2] If implemented in full tool assisted speedruns, this can become entirely ridiculous. That rare thing you need to grind hours to find? nope. just press these 18 buttons starting at the right frame and it'll drop first try. 1: https://www.youtube.com/watch?v=MNQaZFwu57E https://www.youtube.com/watch?v=MNQaZFwu57E 2: https://www.youtube.com/watch?v=-sfE8qLCnQY https://www.youtube.com/watch?v=-sfE8qLCnQY
- tialaramex 3y ago
  Nintendo's relatively modern Mario Maker 2 even deliberately chooses not to have real randomness. "Random" MM2 courses such as "Carlsino" actually rely on subtle differences in player inputs, if you could ensure you don't deviate from a certain series of button presses and timings then the "random" elements would always turn out the same.
  - tetha 3y ago
    Aye. It is a very interesting question if you need or even want full randomness in a game. If you have something that's geared towards speed running, fast execution and mastering, being deterministic is actually a good thing. Otherwise, the player has to re-roll a hundred times to get the "good seed" to get a good run - that's very frustrating. Look at some of the kings quest speedruns for this kinda frustration. Or in a similar direction - tetris with a true random piece selection can result in very frustrating and unwinnable piece sequences (which bastard tetris is dialing to 12). Instead, quite a few modern implementations choose some set of tetrimonios and fill a bag with 3-5 repetitions of this set and choose from that. This limits the possibility and length of possibly frustrating pieces.

defrost 3y ago

A single random password simply isn't enough - Cloudflare deals in millions (actually many many more) of secure handshakes per second. Each has to be secure with a unique unpredictable element. One way (of many) is to use complex PRNG's - Psuedo Random Number Generators, but these can (theorectically) be sequence guessed and then are predictable (or least have a greatly reduced "guess space"). A hybrid way is to regularly reseed a PRNG with a "truly random" starting point, milk that for a few hundred values, and then kick it again with a new random seed. These particular pendulums have "simple" mechanics that are similar to the dynamic systems represented by Lorenz's Butterfly [1] (not exactly but with similar properties) and thus move in chaotic unpredicable ways (such as the timing between the last crossbar changing directions) - these can be "driven" (the base rocked | vibrated) by a small motor) so they continuusly move and yet the path through phase space is still unpredictable. So, without knowing for certain whether this is what Cloudflare is doing here, that is one way in which many many truly random numbers can be generated to feed into secure handshakes; using unpredictable seeds to feed into twisted PRNGs. [1] https://en.wikipedia.org/wiki/Lorenz_system https://en.wikipedia.org/wiki/Lorenz_system

zelphirkalt 3y ago
Seemingly chaotic does not equal random. But unless someone figures out a way to make the chaotic seem no longer chaotic, it will be good enough for our purposes.

GuB-42 3y ago

There are many algorithms where instead of transferring data using a computationally expensive (usually public key, like RSA) algorithm, the data is encrypted with a much faster (usually symmetrical, like AES) algorithm using a random key and then the key is transferred using the expensive algorithm. If you can guess how the random key is generated, then you can decrypt the message without breaking either encryption algorithm. That's why it is important to have really unpredictable random data, and physical randomness is the best for that. In practice, that wall of pendulums is unlikely to make a difference compared to the more mundane techniques used in most computers these days, that rely on some CSPRNG combined with various hard to predict system events (ex: interrupt timing), but it looks way cooler.

moritonal 3y ago

Fun fact, Hackernews itself was "hacked" by a user doing exactly this. A user realised they could successfully guess the key-space the server used to encrypt it's user cookies. Had it had a greater source of random it wouldn't have been possible. https://news.ycombinator.com/item?id=639976 https://news.ycombinator.com/item?id=639976

jgrahamc 3y ago
Amusingly, I had pointed out that HN was vulnerable to such an attack about a month before that user did it. And I was also involved into setting up Cloudflare's Lava Lamps. https://news.ycombinator.com/item?id=640213 https://news.ycombinator.com/item?id=640213

astura 3y ago

Here's an (old) example of poor random number generation leading to an exploit - https://www.developer.com/guides/how-we-learned-to-cheat-at-online-poker-a-study-in-software-security/ https://www.developer.com/guides/how-we-learned-to-cheat-at-...