
Security
eMudhra’s CA Keys Were Compromised Because a Private Key Was the Number 4.
In October 2026, Mozilla and Google confirmed that 8 intermediate signing keys from eMudhra, 1 of the few Indian certificate authorities trusted globally, had private keys a laptop can guess in under a second, including 1 that was literally the integer 4. I went through how a secret that should be 116 digits long collapsed to single digits, how browsers shut it down in under 3 hours, why your backend servers may still be exposed, and why, for a certificate authority, the incident is survivable but the response decides everything.