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[freehaven-cvs] still more cleanups
Update of /home/freehaven/cvsroot/doc/fc03
In directory moria.seul.org:/home/arma/work/freehaven/doc/fc03
Modified Files:
econymics.tex
Log Message:
still more cleanups
Index: econymics.tex
===================================================================
RCS file: /home/freehaven/cvsroot/doc/fc03/econymics.tex,v
retrieving revision 1.13
retrieving revision 1.14
diff -u -d -r1.13 -r1.14
--- econymics.tex 15 Sep 2002 19:50:14 -0000 1.13
+++ econymics.tex 15 Sep 2002 20:16:33 -0000 1.14
@@ -334,9 +334,9 @@
\begin{itemize}
\item through the mix-net system, $c_{s}$. This cost includes both
-direct financial costs of using of the system (e.g., usage fees), as well as
-implicit costs such as the time needed to configure messages in order for
-them to be used in the system, or delays incurred when using the system.
+direct financial costs such as usage fees, as well as implicit costs
+such as the time to build an anonymous message, learning curve to get
+familiar with the system, and delays incurred when using the system.
These delays should be positively correlated to the traffic $n_{s}$ and
negatively correlated to the number of nodes $n_{h}$.
% FIXME is this right? -RD
@@ -345,7 +345,7 @@
reduce risk. We could assign a higher $c_{s}$ to longer routes to reflect
the cost of additional delay.
-\item or through a conventional, non anonymous system, $c_{n}$.
+\item or through a conventional non-anonymous system, $c_{n}$.
\end{itemize}
\item receiving dummy traffic, $c_{r}$.
@@ -363,28 +363,22 @@
\end{enumerate}
In addition to the above costs and benefits, there might also be
-\emph{reputation} costs and benefits from:
-
-\begin{itemize}
-\item using the system to send messages (e.g., there can be a reputation
-cost of being exposed as a sender of anonymous messages even though the
-messages themselves do remain anonymous),
-
-\item acting as a perceivably honest node (e.g., there can be a reputation
-benefit by acting as a reliable node),
-
-\item acting as a perceivably dishonest node (e.g., there can be a reputation
-cost by being exposed as a dishonest node; the costs here will also be a
-function of the probability of being exposed as a bad node).
-\end{itemize}
+\emph{reputation} costs and benefits from using the system to send
+messages (e.g., there can be a reputation cost of being exposed as a
+sender of anonymous messages even though the messages themselves do
+remain anonymous), acting as a perceivably honest node (e.g., there can
+be a reputation benefit by acting as a reliable node), or acting as a
+perceivably dishonest node (e.g., there can be a reputation cost by being
+exposed as a dishonest node; the costs here will also be a function of
+the probability of being exposed as a bad node).
These reputation costs and benefits can be considered ``internal''
to the system (for example, being perceived as a honest node brings
that node more traffic, and therefore more possibilities to hide that node's
messages; similarly, being perceived as a dishonest node might bring traffic
-away from that node). In this case they will not enter directly the utility
-functions of the agents, but will enter indirectly through the changes they
-provoke in the behavior of the agents.
+away from that node). Thus they do not enter directly the utility
+functions of the agents, but rather enter indirectly through the changes
+they provoke in the behavior of the agents.
We assume that agents want to maximize their expected utility, which is
a function of expected benefits minus expected costs. We represent the payoff
@@ -401,37 +395,35 @@
where $u,\theta ,\gamma $, and $\partial $ are unspecified functional forms.
The payoff function $u$ includes the costs and benefits for all the possible
-actions of the agents, including \textit{non} using the mix-net but sending
-the messages through a non anonymous channel. We can simply represent these
-actions with dummy variables $a_{i}$s.\footnote{%
-For example, in case where the agent chooses not to send the message
-anonymously, the probability of remaining anonymous, $p_{a}$ will be equal
+actions of the agents, including \textit{not} using the mix-net and
+instead sending the messages through a non-anonymous channel. We can
+represent these actions with dummy variables $a_{i}$.\footnote{%
+For example, if the agent chooses not to send the message
+anonymously, the probability of remaining anonymous $p_{a}$ will be equal
to zero, $a^{s,d,r,h}$ will be zero too, and the only cost in the function
-will be $c_{n}$.} Note that $\gamma $ and $\partial \ $represents functions
-of (among other items) the probability of a message being delivered and a
+will be $c_{n}$.} Note that $\gamma $ and $\partial$ describe
+the probability of a message being delivered and a
message remaining anonymous, respectively. These probabilities are weighted
-with the values $v_{r,a}$ because different $i$s might value anonymity and
-reliability differently,\footnote{%
-In other words, even if agents agree on a metrics for reliability and a
-metrics for anonymity, some might care more about anonymity than
-reliability, some viceversa.} and because in different scenarios anonymity
+with the values $v_{r,a}$ because different agents might value anonymity and
+reliability differently,%\footnote{%
+%In other words, even if agents agree on metrics for reliability and
+%anonymity, some might care more about anonymity than
+%reliability, some vice versa.}
+and because in different scenarios anonymity
and reliability for the same agent might have different impacts on her
payoff.
-Consider in fact that a message could be sent anonymously to avoid costs or
-to gain profits; furthermore, the costs or benefits from sending the message
-might be distinct from the costs or benefit from keeping the information
-anonymous.\footnote{%
-For example:\ an agent sends a message to a merchant containing anonymous
-financial information in order to purchase a book at a special deal. The
-agent will gain a profit equal to the difference between her evaluation of
-the good and its price. If the anonymity of the financial information is
-compromised during the process, however, the agent this might incur losses
-of amount completely independent from the price of the book or its
-evaluation by the agent.} Hence the payoff function $u_{i}$ above allows us
-to represent the duality implicit in all privacy issues, as well as the
-distinction between the value of sending a message and the value of keeping
-it anonymous:
+While messages might be sent anonymously to avoid costs or to gain
+profits, the costs and benefits from sending the message might be
+distinct from the costs and benefits from keeping the \emph{information}
+anonymous. For example, when Alice anonymously contacts a merchant
+to purchase a book, she will gain a profit equal to the difference
+between her evaluation of the good and its price. But if her anonymity
+is compromised during the process, she will incur losses completely
+independent from the price of the book or her valuation of it. The payoff
+function $u_{i}$ above allows us to represent the duality implicit in
+all privacy issues, as well as the distinction between the value of
+sending a message and the value of keeping it anonymous:
\begin{equation*}
\begin{tabular}{cc}
@@ -711,7 +703,7 @@
[[extend from here on]]
-when v$_{1}>>v_{2}$ then equilibrium with free-riding can be sustained. \cite
+when $v_{1}>>v_{2}$ then equilibrium with free-riding can be sustained. \cite
{palfrey-rosenthal-89}\footnote{%
Show proof for a specific probability function here [[extend]].}
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