They don’t need to sync for it to be a serious weakness in a cryptosystem. If a system using Khoth’s PRNG sends out a billion encrypted messages in its lifetime, then an attacker with the PRNG key needs less than 2^30 tries to decrypt a message sent at an unknown point in that sequence—a large number, but more than manageable when you consider that a PRNG with a period of 2^80 would be considered weak in the crypto world.
How does the NSA synchs with your “RNG” is no information is exchanged?
But anyway, if you reasonably believe that your RNG may have been compromised, then you just don’t use it.
They don’t need to sync for it to be a serious weakness in a cryptosystem. If a system using Khoth’s PRNG sends out a billion encrypted messages in its lifetime, then an attacker with the PRNG key needs less than 2^30 tries to decrypt a message sent at an unknown point in that sequence—a large number, but more than manageable when you consider that a PRNG with a period of 2^80 would be considered weak in the crypto world.
Agreed.