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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