diff --git a/doc/design-paper/sptor.tex b/doc/design-paper/sptor.tex index eaa2f04281..9daa686c87 100644 --- a/doc/design-paper/sptor.tex +++ b/doc/design-paper/sptor.tex @@ -71,20 +71,22 @@ logical or physical locations to those sites or to observers. It enables hosts to be publicly accessible yet have similar protection against location through its \emph{location-hidden services}. -To connect to a remote server via Tor, the client software learns +To connect to a remote server via Tor the client software first learns a %signed list of Tor nodes from several central \emph{directory servers} via a -voting protocol to avoid dependence on or complete trust in any one of -them, and incrementally creates a private pathway or \emph{circuit} of -encrypted connections through authenticated Tor nodes on the network -whose public keys were obtained form the directory servers, -negotiating a separate set of encryption keys for each hop along the +voting protocol (to avoid dependence on or complete trust in any one +of these servers). It then incrementally creates a private pathway or +\emph{circuit} across the network. This circuit consists of +encrypted connections through authenticated Tor nodes +whose public keys were obtained from the directory servers. The client +software negotiates a separate set of encryption keys for each hop along the circuit. The nodes in the circuit are chosen at random by the client subject to a preference for higher performing nodes to allocate resources effectively and with a client-chosen preferred set of first nodes called \emph{entry guards} to complicate profiling attacks by internal adversaries~\cite{hs-attack}. -The circuit is extended one node at a time, and each node +The circuit is extended one node at a time, tunneling extensions +through already established portions of the circuit, and each node along the way knows only the immediately previous and following nodes in the circuit, so no individual Tor node knows the complete path that each fixed-sized data packet (or \emph{cell}) will take. Thus,