changeset 293:e426b4d5049b

Minor correction
author Sigurd Meldgaard <stm@daimi.au.dk>
date Tue, 13 Apr 2010 12:24:31 +0200
parents e1a9ebd21a09
children c90a87064b34
files provsec/paper.tex
diffstat 1 files changed, 20 insertions(+), 6 deletions(-) [+]
line wrap: on
line diff
--- a/provsec/paper.tex	Mon Apr 12 15:19:01 2010 +0200
+++ b/provsec/paper.tex	Tue Apr 13 12:24:31 2010 +0200
@@ -50,7 +50,7 @@
 
 \section{Concepts}
 Secure multi-party computation (MPC) deals with scenarios where a
-number of players each possess some private data, and we want to
+number of players each possess some private data, and want to
 compute a certain result from these data without revealing anything
 except for the intended result. There are numerous examples of such
 scenarios. Examples include Elections, Auctions, Procurement,
@@ -296,6 +296,11 @@
 on the data computed on, via a text-string given as input to
 \KWD{precondition}.
 
+A function marked \verb|ideal_functionality| cannot be called from
+functions that are not themselves marked (this is implemented in
+practice by renaming them, and updating every call inside a marked
+function.)
+
 \section{Example}
 
 In this section we give a toy example demonstrating some of the ideas
@@ -668,17 +673,21 @@
 what is marked as \verb|result| in $P$. At all times $F_P$ will tell
 the adversary where in the program execution it is.
 
-We now want to show that $pi_P$ with acces to $F$ is implementing
+We now want to show that $pi_P$ with access to $F$ is implementing
 $F_P$.
 
-The main thing we need to show, is that any \verb|open| that $pi_P$
-will do, can only release information (do an \verb|open|) when there
+The main property we need to show, is that any \KWD{open} that $pi_P$
+will do, can only release information (do an \KWD{open}) when there
 is a way to simulate this output from the information $F_P$ outputs
 from the $result$ instructions.
 
 Also we need to show that the only parts of $pi_P$ that can
-\verb|open| information are the ones that are marked by
-\verb|@ideal_functionality|.
+\KWD{open} information are the ones that are marked by
+\KWD{@ideal\_functionality}: The secret information can only be
+created by those functions, and they cannot be called but from within
+themselves. And they cannot pass the information on to other
+functions, so we always have that secret information is only handled
+within these, and therefore they are the only ones that can \KWD{open} it.
 
 %Givet semantikken af sproget burde det være indlysende hvad
 %protokollen gør: spillerne kører gennem P (i hovedet så et sige), de sender input til F når P indeholder
@@ -705,6 +714,11 @@
 %(af if's), så vil beviset automatisk skulle indeholde et bevis for at omskrivningen af if's på
 %hemmelige værdier er OK.
 
+The security of the implemented protocol is thus inherited from the
+primitives of the runtime. In VIFF there exists several different
+runtimes with different security characteristics with respect to
+correctness, passive/active security, termination etc.
+
 \section{Example: Binary Search in Auctions}
 A known example of secure multi-party computation used in practice is
 for determining the so called market clearing price from the bids of