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Name | Lifetime | Created by | Type | Purpose |
---|---|---|---|---|
User key | Persistent | User | Public | Identify a user to the server |
Session key | One session | Client (and server) | Secret | Protect communications |
Host key | Persistent | Administrator | Public | Identify a server/machine |
Server key | One hour | Server | Public | Encrypt the session key (SSH1 only) |
TIP: SSH-1 uses a single session key, but SSH-2 has several: each direction (server to client, and client to server) has keys for encryption and others for integrity checking. In our discussions we treat all SSH-2's session keys as a unit and speak of "the session key" for convenience. If the context requires it, we specify which individual key we mean.
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3.2. A Cryptography Primer | ![]() | 3.4. Inside SSH-1 |
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