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author | Roger Dingledine <arma@torproject.org> | 2004-02-01 05:19:49 +0000 |
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committer | Roger Dingledine <arma@torproject.org> | 2004-02-01 05:19:49 +0000 |
commit | fa0c7c5a47ada27df055c3f156edc0dd4297649b (patch) | |
tree | 5242238db5dd3983e269a6314673665f9ff6a981 /doc | |
parent | 20f56091cec0f3ac25a7538bfc560b1540cc8d43 (diff) | |
download | tor-fa0c7c5a47ada27df055c3f156edc0dd4297649b.tar.gz tor-fa0c7c5a47ada27df055c3f156edc0dd4297649b.zip |
put the appendix on its own page; make it only one page
svn:r1049
Diffstat (limited to 'doc')
-rw-r--r-- | doc/tor-design.tex | 55 |
1 files changed, 29 insertions, 26 deletions
diff --git a/doc/tor-design.tex b/doc/tor-design.tex index 1107328503..40fdb082c6 100644 --- a/doc/tor-design.tex +++ b/doc/tor-design.tex @@ -1814,21 +1814,23 @@ our overall usability. \bibliographystyle{latex8} \bibliography{tor-design} +\newpage \appendix \Section{Rendezvous points and hidden services} \label{sec:rendezvous-specifics} -In this appendix we provide more specifics about the rendezvous points -of Section~\ref{subsec:rendezvous}. We also describe integration -issues and related work. +In this appendix we provide specifics about the rendezvous points +of Section~\ref{subsec:rendezvous}. % We also describe integration +%issues and related work. %, and how well the rendezvous point design %withstands various attacks. % (Not any more; it's currently commented out. -NM) - -\SubSection{Rendezvous protocol overview} - -We give an overview of the steps of a rendezvous. These are +% +%\SubSection{Rendezvous protocol overview} +% +The following steps are +%We give an overview of the steps of a rendezvous. These are performed on behalf of Alice and Bob by their local OPs; application integration is described more fully below. @@ -1873,14 +1875,17 @@ introduction points for his service, and periodically refreshes his entry in the DHT. The message that Alice gives -the introduction point includes a hash of Bob's public key to identify -the service, along with an optional initial authorization token (the +the introduction point includes a hash of Bob's public key % to identify +%the service, along with +and an optional initial authorization token (the introduction point can do prescreening, for example to block replays). Her message to Bob may include an end-to-end authorization token so Bob can choose whether to respond. The authorization tokens can be used to provide selective access: -important users get tokens to ensure uninterrupted access to the -service. During normal situations, Bob's service might simply be offered +important users can get uninterrupted access. +%important users get tokens to ensure uninterrupted access. %to the +%service. +During normal situations, Bob's service might simply be offered directly from mirrors, while Bob gives out tokens to high-priority users. If the mirrors are knocked down, %by distributed DoS attacks or even @@ -1888,17 +1893,16 @@ the mirrors are knocked down, those users can switch to accessing Bob's service via the Tor rendezvous system. -Since Bob's introduction points might themselves be subject to DoS he -could have to choose between keeping many -introduction connections open or risking such an attack. In this case, -he can provide selected users -with a current list and/or future schedule of introduction points that -are not advertised in the DHT\@. This is most likely to be practical +Bob's introduction points are themselves subject to DoS---he must +open many introduction points or risk such an attack. +He can provide selected users with a current list or future schedule of +unadvertised introduction points; +this is most practical if there is a stable and large group of introduction points -available. Alternatively, Bob could give secret public keys -to selected users for consulting the DHT\@. All of these approaches -have the advantage of limiting exposure even when -some of the selected users collude in the DoS\@. +available. Bob could also give secret public keys +for consulting the DHT\@. All of these approaches +limit exposure even when +some selected users collude in the DoS\@. \SubSection{Integration with user applications} @@ -1914,7 +1918,7 @@ remains a SOCKS proxy. We encode all of the necessary information into the fully qualified domain name Alice uses when establishing her connection. Location-hidden services use a virtual top level domain called {\tt .onion}: thus hostnames take the form {\tt x.y.onion} where -{\tt x} is the authorization cookie, and {\tt y} encodes the hash of +{\tt x} is the authorization cookie and {\tt y} encodes the hash of the public key. Alice's onion proxy examines addresses; if they're destined for a hidden server, it decodes the key and starts the rendezvous as described above. @@ -1928,17 +1932,16 @@ of mobile phones and low-power location trackers~\cite{federrath-ih96,reed-protocols97}. Rendezvous for low-latency Internet connections was suggested in early Onion Routing -work~\cite{or-ih96}; however, the first published design of rendezvous -points for low-latency Internet connections was by Ian +work~\cite{or-ih96}, but the first published design was by Ian Goldberg~\cite{ian-thesis}. His design differs from ours in three ways. First, Goldberg suggests that Alice should manually hunt down a current location of the service via Gnutella; our approach makes lookup transparent to the user, as well as faster and more robust. Second, in Tor the client and server negotiate session keys via Diffie-Hellman, so plaintext is not exposed even at the rendezvous point. Third, -our design tries to minimize the exposure associated with running the +our design minimizes the exposure from running the service, to encourage volunteers to offer introduction and rendezvous -point services. Tor's introduction points do not output any bytes to the +services. Tor's introduction points do not output any bytes to the clients; the rendezvous points don't know the client or the server, and can't read the data being transmitted. The indirection scheme is also designed to include authentication/authorization---if Alice doesn't |