4 ms·

> There is nothing ridiculous about using random.org, though that should be https. Everything is wrong about this. • You can not trust SSL to protect your sou

by nwh 13y ago

> There is nothing ridiculous about using random.org, though that should be https. Everything is wrong about this. • You can not trust SSL to protect your source of entropy. • You can not trust an external, unverified source of entropy.

Dylan16807 13y ago
Pretend for a moment that you have isolated hardware with no trusted random sources. And this hardware already depends on large secret binary blobs to run at all. At this point trust is already hard, and random.org is a hell of a lot better than nothing. If you mix network jitter with external randomness sources that's just about the best possible job you can do. Neither half is perfect but they help.
- nwh 13y ago
  Every linux distro has /dev/random as a good, cryptographically secure source of randomness that is refilled by as many sources as possible. It can and has been audited by many developers to ensure this. The main issue you will have is having multiple identical instances of a linux VM built from a single source, or something like that. Alternatively, you suggest a sole remote source over a public internet connection. Assuming an eavesdropper, the source could be compromised or the strength of the resulting cipher be reduced. Assuming a malicious entity with network control, you're pretty much screwed. If you don't trust your hardware, you can't be working with encryption.
  - Dylan16807 13y ago
    Software can only do so much without good hardware sources. A small embedded box, barred from networking, has roughly zero entropy available. But if you combine microsecond network timings, only vulnerable to local attack, with third party random data that is safe from mitm, you get resonably good random numbers. Don't use it to generate a root certificate, but it'll work for general purposes.
    - marshray 13y ago
      > Don't use it to generate a root certificate, but it'll work for general purposes. "General purposes" is exceedingly hard to quantify.
      - Dylan16807 13y ago
        How about this: it's much easier for an attacker to physically compromise the device than it is for them to attack your network AND attack random.org. Is that not good enough? It's about as secure as your average desktop. You can't make a device more secure than the access to it, and there is no such thing as perfect security.

by nwh 13y ago

Dylan16807 13y ago

Pretend for a moment that you have isolated hardware with no trusted random sources. And this hardware already depends on large secret binary blobs to run at all. At this point trust is already hard, and random.org is a hell of a lot better than nothing. If you mix network jitter with external randomness sources that's just about the best possible job you can do. Neither half is perfect but they help.

nwh 13y ago
Every linux distro has /dev/random as a good, cryptographically secure source of randomness that is refilled by as many sources as possible. It can and has been audited by many developers to ensure this. The main issue you will have is having multiple identical instances of a linux VM built from a single source, or something like that. Alternatively, you suggest a sole remote source over a public internet connection. Assuming an eavesdropper, the source could be compromised or the strength of the resulting cipher be reduced. Assuming a malicious entity with network control, you're pretty much screwed. If you don't trust your hardware, you can't be working with encryption.
- Dylan16807 13y ago
  Software can only do so much without good hardware sources. A small embedded box, barred from networking, has roughly zero entropy available. But if you combine microsecond network timings, only vulnerable to local attack, with third party random data that is safe from mitm, you get resonably good random numbers. Don't use it to generate a root certificate, but it'll work for general purposes.
  - marshray 13y ago
    > Don't use it to generate a root certificate, but it'll work for general purposes. "General purposes" is exceedingly hard to quantify.
    - Dylan16807 13y ago
      How about this: it's much easier for an attacker to physically compromise the device than it is for them to attack your network AND attack random.org. Is that not good enough? It's about as secure as your average desktop. You can't make a device more secure than the access to it, and there is no such thing as perfect security.