Message #125368

[Lionel Debroux]

Quoting myself from reply #71 in this very topic:

We've already had lots of talk about factoring the key, in another topic (but it's understandable that you missed it: there's lots of activity on the forum, and that is a good thing): http://www.omnimaga.org/index.php?topic=3639.0

I have summarized multiple times how impractical the factorization is (unless some ground-breaking algorithm comes to the rescue, which we should not hold our breath on): basically, three orders of magnitude harder than the state of the art.
A linear extrapolation of the figures given in the paper detailing the factorization of RSA-768, consistent with what we know of 512-bit RSA factoring, gives the need of sifting through 10000-100000 TB (yes, I really mean terabytes) of data, after those have been produced by several dozen thousands of computers running for years (or ten times as many computers, running for one tenth of the time).
This does not, however, mean that we can't spend up to several CPU-years trying to find a factor by Trial Factoring (beyond that would not be reasonable): it's extremely unlikely that we'll succeed by sifting through a search space which represents an vanishingly small part of a particle, compared to the whole universe - but such is the beauty of random.