Post
Topic
Board Development & Technical Discussion
Re: ECDSA Weak signing
by
kjj
on 10/09/2013, 11:13:46 UTC
If you go around disallowing a bunch of K values then you're decreasing security not increasing it... Though I would agree that this specific test is perhaps mildly useful as a "RNG fatally broken, do not pass go" check.

I don't see why K==d is more indicative of a faulty RNG than the infamous K==11 ? Are you seriously suggesting that we should test here whether we're dealing with RNG that always returns the same value, or is there something else that I'm missing?

Actually, I suggested it.

If you test for a single value of k, that test will never ever trip because the odds of drawing that one k is zero (approximately).  It doesn't matter if the value under test is D or a constant.  The exception is when your RNG is broken, perhaps XCKD-style.