 | Passwords can not go in the clear. The password needs hashing |
| A replay should not be possible Use "number once" |
Authentication using symmetric keys:
| Instead of hashing, symmetric keys are used |
Authentication using public keys:
| What ever we can do with symmetric keys, we can do with public keys |
Session keys: Key for confidentiality or integrity protection or both for the current session.
| Still needs authentication |
Perfect forward secrecy PFS:
| Using a session key so that the mutual key can not be used in the future for Trudy to decrypt a recorded messages. |
Timestamps:
| Can be used in place of a nounce |
| Saves messages going back and forth, exchaning nonces |