"The CA of concern in this case is called eMudhra, which boasts of having issued over 60 million digital certificates...
"'Not a number that starts with 4, or the number 4 followed by a few hundred random digits, just, 4... Another one is 56, and another is 115....' Other researchers have found private keys including the numbers 66, 155, 156, 230 and 237."
(i swear I'm not threadsitting) fwiw, these private keys had just as many bytes as every other 384-bit key. It's just that most of the bytes were zero.
@ardgedee And therefore 4 is a perfectly good private key, in a perfect world! Like, it's as hard to guess as anything other number in that 2^348 range.
In an imperfect world, someone miiiiiight fuck up their keygen process in a way that drastically reduces the search space. So doing checking small values in the extremely unlikely event that someone fucks up accordingly turns out to pay off (in a "discovering a catastrophic problem" sense if you're not a hostile actor).
"The CA of concern in this case is called eMudhra, which boasts of having issued over 60 million digital certificates...
"'Not a number that starts with 4, or the number 4 followed by a few hundred random digits, just, 4... Another one is 56, and another is 115....' Other researchers have found private keys including the numbers 66, 155, 156, 230 and 237."
https://xkcd.com/221/
In an imperfect world, someone miiiiiight fuck up their keygen process in a way that drastically reduces the search space. So doing checking small values in the extremely unlikely event that someone fucks up accordingly turns out to pay off (in a "discovering a catastrophic problem" sense if you're not a hostile actor).