Eight Bits of Trust; eMudhra's CA keys cracked in milliseconds

Automated excerpt

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... A P-384 private key should be a random 384-bit number, which gives you 2³⁸⁴ possibilities (or roughly 10¹¹⁵), so nobody is ever going to search that. eMudhra's keys look like this:d = 0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000004 A P-384 private key should look like this:d = 0x48ac06790886c80c48d31691fd4c0fe9ce3207f9807f2fe571d6e4ec426d78644298fc53df2b92566970e757ac998c34That's 47 bytes of zeros and then one byte, and all eight keys are like that. The key was effectively public from the day the certificate existed.

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