Eight Bits of Trust; Emudhra's Ca Keys Cracked in Milliseconds

One of eMudhra’s certificate authority private keys is the number 4.

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. I know, because I recovered all of them from their public certificates on my laptop just now, and it took less than a second.

— Eight Bits of Trust; eMudhra’s CA keys cracked in milliseconds by Scott Helme