4 ms·

It mentions only "key exchange method". Does it mean we can keep our old keys or it requires different types of keys to be used?

• sz3 5y ago
  Different keys. For example, you might currently be using a public/private keypair for 4096-bit RSA. That keypair (by definition) only works for the RSA key exchange algorithm. Likewise, an x22519 keypair is for the x25519 key exchange. A sntrup761x25519 keypair will be its own thing. As an aside, a sntrup761x25519 public key will be two public keys glued together (one for each algorithm). [1] Likewise for the private key. (one could reuse an existing x25519 keypair for the x25519 component of sntrup761x25519, but it seems like a bad idea) [1] https://github.com/openssh/openssh-portable/blob/master/kexsntrup761x25519.c#L42-L70 https://github.com/openssh/openssh-portable/blob/master/kexs...
  • ttybird2 5y ago
    Same keys, servers and clients will keep using their ed25519 keys for authenticating each other, the keys for the key exchange are negotiated on login.
    • sz3 5y ago
      Huh! Thanks for the correction. That makes a lot of sense -- I have some more reading to do...