Soatok Dreamseeker on Nostr: nprofile1q…kgykp why is it important for a messenger to have PFS? A protocol with ...
nprofile1qy2hwumn8ghj7un9d3shjtnddaehgu3wwp6kyqpq3385x9zu5czskpud40ukzc2m0hhjr9f0kckk79uq293qxty78vrsckgykp (nprofile…gykp)
why is it important for a messenger to have PFS?
A protocol with PFS looks something like this:
Client->Server: "Give me a one-time public key, and sign it so I know it's yours."
Server->Client: "Here you go."
Client validates the signature.
Client->Server: "Thanks, here's some data encrypted under a symmetric key, that only the secret key corresponding to your public key can decrypt."
Server: "Cool. Here's some more ciphertext."
Server shreds secret key for that public key.
If you intercept the encrypted traffic now, and then hacked the server later, you wouldn't have a secret key to retrieve.
Conversely, if everything was encrypted against the long-term public key provided by the server, once you've popped the box you can decrypt all previous handshakes.
That's in the TLS use case, anyway.
E2EE is a bit more sensitive, since it's used for actual comms between people (and there isn't as much bot traffic to filter out). Higher signal/noise ratio.
why is it important for a messenger to have PFS?
A protocol with PFS looks something like this:
Client->Server: "Give me a one-time public key, and sign it so I know it's yours."
Server->Client: "Here you go."
Client validates the signature.
Client->Server: "Thanks, here's some data encrypted under a symmetric key, that only the secret key corresponding to your public key can decrypt."
Server: "Cool. Here's some more ciphertext."
Server shreds secret key for that public key.
If you intercept the encrypted traffic now, and then hacked the server later, you wouldn't have a secret key to retrieve.
Conversely, if everything was encrypted against the long-term public key provided by the server, once you've popped the box you can decrypt all previous handshakes.
That's in the TLS use case, anyway.
E2EE is a bit more sensitive, since it's used for actual comms between people (and there isn't as much bot traffic to filter out). Higher signal/noise ratio.