% File              : ccittx509_1c.tex
% Version           : $Revision: 1.1 $
% Last-modified     : $Date: 2005/01/04 11:45:32 $
% Last-modifier     : FJ

\documentclass{splib}

\begin{document}
% main environment
\begin{protocol}%
% name
{CCITT X.509 (1c)}%
% authors
{M. Abadi and R Needham}%
% date of the first publication
{1996}%
% editor name
{}%
% date of submission
{}%
% date of last change, empty or = date of submission
{11/11/2002}

\begin{abstract}
Correction of the \crossref{ccittx509_1} one message protocol.
\end{abstract}

\begin{core}
\begin{declarations}
\dcl{A, B}{principal}
\dcl{Na, Nb}{nonce}
\dcl{Ta, Tb}{timestamp}
\dcl{Ya, Yb}{userdata}
\dcl{Xa, Xb}{userdata}
\dcl{PK, SK}{principal -> key (keypair)}
\dcl{h}{userdata -> userdata (one-way)}
\end{declarations}

\begin{messages}
\msg{1}{A}{B}{A, \crypt{Ta, Na, B, Xa, 
              \crypt{Ya, \crypt{h(Ya)}{SK(A)}}{PK(B)}}{SK(A)}}
\end{messages}
\end{core}

\begin{explanation}
See \crossref{ccittx509_1}.
The solution proposed in \cite{abadi96prudent}
to correct the authentication flaw  
in the \crossref{ccittx509_1} one message protocol
is to sign the secret data \code{Ya} before it is encrypted.
\end{explanation}

\begin{property}
The protocol must ensure the recipient \code{B} of the message
that the data \code{Xa} and \code{Ya} originate from \code{A}.
\end{property}

\begin{references}
\cite{abadi96prudent}, 
\cite{CCITT_X.509}.
\end{references}

\begin{see} %\crossref{}, see all.aux for labels names
\crossref{ccittx509_1},
\crossref{ccittx509_3}.
\end{see}

\end{protocol}
\end{document}

%%% Local Variables: 
%%% mode: latex
%%% TeX-master: t
%%% End: 
