I believe this is related to Are the wrong questions and answers getting too many upvotes?.
I am wondering what should be done when a popular question is getting answers that are downright incorrect, to the point of being dangerous? When it's just one answer, the solution is simple, but in this case it is nearly all answers, and they all have high upvotes.
How great is the risk in publicly sharing part of a private key? is the question in mind. In it, someone is asking what the danger of revealing a small part of the private key is. While his example size was 256 bits, it seemed fairly clear that he was talking about public key cryptography. The answers involved some of the following (paraphrased):
- Why would you want to do that? Just share the public key.
- Leaking only a tiny bit doesn't matter. A 4k key with 2048 bit leaked still has a 22048 keyspace.
- Brute force is easier than factoring so it's fine to leak a little bit.
- It doesn't matter what part of the key is leaked. n bits is n bits.
All of these are incorrect or non-answers. For example, it is untrue that leaking a small bit of a private key is safe, because only a tiny tiny fraction can completely destroy the security, whereas if all that is leaked is the exponent, no security is lost at all. I found only one answer that was correct in the comments:
All information in a private key is not equal, so there is no "equivalent factor". Leak the modulus or public exponent and nothing happened (versus sharing the public key). Leak "50%" of the prime numbers and you're 100% boned
However, this patently incorrect comment has double the upvotes:
As factoring semiprimes is assumed to be so secure that brute force is the best possible attack
This should not be happening, especially with something this basic. If this question were moved to Crypto.SE, the answers wouldn't even be close to acceptable. What can be done about this? Should it be moved to Crypto.SE to let the answers get the downvotes they deserve? Should I just ignore it and move on?