[tor-talk] Tor Design : Differents keys used for connection.

[Roger Dingledine]

On Thu, May 19, 2016 at 10:13:54PM +0200, Brieuc Barthélemy wrote:
> In point 4 (Page 4) the article talks about differents keys:
> - A long term identity key: to sign TLS certificate, OR route descriptor
> and to sign directories.
> - A short-term onion key: used to decrypt requests from users.
> - Ephemerals keys ( first words on page 5 )
> - And "link keys" for TLS communication.
> 
> My question is: do you think the last two of them ( Ephemerals and link
> eyes ) are the same one ?
> Because I don't find any clear informations about those "ephemerals"

You might enjoy
https://www.torproject.org/docs/faq#KeyManagement

It sounds like the 'ephemeral keys' you mention could be the circuit-level
keys, that is, the symmetric keys negotiated by the circuit handshake
and used for the lifetime of that circuit.

--Roger