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I know of these keys that exist within NTS:<br>
<br>
* client-to-server (c2s)<br>
<br>
* server-to-client (s2c)<br>
<br>
* server master key<br>
<br>
The master key is shared between NTPD and NTS-KE (mechanism
currently undecided). It is used to encrypt data in cookies and is
never seen outside of the NTPD/NTS-KE pair. *The client never sees
this key*. The master key is also expected to be rotated on a
regular basis: the example in section 6 of the draft has once a day
rotation.<br>
<br>
The c2s/s2c pair is created during the TLS handshake between NTS-KE
and the client. They are expected to be embedded within the
encrypted part of the cookie so that the server does not need to
store any per-client state. No mention is made of rotating these,
though it could be done through invalidation with NAK.<br>
<br>
An important detail is that because the client never has access to
any master key, the client is not able to see inside or change the
cookie. This is true even if the client knows the cookie format of
the server that it is talking to. Because of this it is impossible
for the server or client to update the c2s/s2c pair by sending new
ones in a cookie.<br>
<br>
<div class="moz-signature">-- <br>
<i>"In the end; what separates a Man, from a Slave? Money? Power?
No. A Man Chooses, a Slave Obeys."</i> -- Andrew Ryan
<p>
<i>"Utopia cannot precede the Utopian.
It will exist the moment we are fit to occupy it."</i> --
Sophia Lamb
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<p>
I work for the <a href="https://icei.org/">Internet Civil
Engineering Institute</a>, help us save the Internet from
Entropy!
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