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If a judge hands down a National Security Letter (NSL) to a CA to turn over its private keys, can the private keys be used to decrypt the communications of all
by orangepurple 5y ago
If a judge hands down a National Security Letter (NSL) to a CA to turn over its private keys, can the private keys be used to decrypt the communications of all traffic that depends on that CA?
- NovemberWhiskey 5y agoNo; the certificate signing request that a CA uses to construct a certificate doesn't have the private key - that should never leave the control of the site owner.
- hsbauauvhabzb 5y agoAs far as I’m aware no, but it would allow the holder to resign a new keypair and Person in the middle traffic, provided they’re able to intercept and modify traffic
- wolrah 5y agoCorrect, and certificate transparency exists pretty much specifically to counter this threat. By requiring certificates to be publicly logged to be valid it becomes trivial for domain owners to monitor all publicly valid certificates in existence for their domain(s). A CA that has been compromised or is being compelled by a government can still issue a valid certificate, but it becomes impossible to hide both that it was done and who did it.