explain that the authentication step is what allows the distributed trust property
Roger Dingledine

Roger Dingledine commited on 2012-02-06 23:33:40
Zeige 1 geänderte Dateien mit 7 Einfügungen und 3 Löschungen.

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@@ -1550,7 +1550,8 @@ the same geographic location.
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     <b>Encryption</b>: first, all connections in Tor use TLS link encryption,
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     so observers can't look inside to see which circuit a given cell is
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     intended for. Further, the Tor client establishes an ephemeral encryption
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-    key with each relay in the circuit, so only the exit relay can read
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+    key with each relay in the circuit; these extra layers of encryption
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+    mean that only the exit relay can read
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     the cells. Both sides discard the circuit key when the circuit ends,
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     so logging traffic and then breaking into the relay to discover the key
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     won't work.
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@@ -1559,11 +1560,14 @@ the same geographic location.
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     <p>
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     <b>Authentication</b>:
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     Every Tor relay has a public decryption key called the "onion key".
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+    Each relay rotates its onion key once a week.
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     When the Tor client establishes circuits, at each step it <a
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     href="<svnprojects>design-paper/tor-design.html#subsec:circuits">demands
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     that the Tor relay prove knowledge of its onion key</a>. That way
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     the first node in the path can't just spoof the rest of the path.
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-    Each relay rotates its onion key once a week.
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+    Because the Tor client chooses the path, it can make sure to get
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+    Tor's "distributed trust" property: no single relay in the path can
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+    know about both the client and what the client is doing.
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     </p>
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     <p>
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@@ -1576,7 +1580,7 @@ the same geographic location.
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     of all the known relays, and in that list are a set of certificates from
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     each relay (self-signed by their identity key) specifying their keys,
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     locations, exit policies, and so on. So unless the adversary can control
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-    a majority of the directory authorities (as of 2011 there were 8
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+    a majority of the directory authorities (as of 2012 there are 8
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     directory authorities), he can't trick the Tor client into using
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     other Tor relays.
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     </p>
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