\begin{thebibliography}{1}

\bibitem{BihamSh93}
E. Biham and A. Shamir.
\newblock {\it A Differential Cryptanalysis of the Data Encryption Standard}.
\newblock Springer-Verlag, 1993.

\bibitem{Matsui94}
Mitsuru Matsui.
\newblock The first experimental cryptanalysis of the data encryption standard.
\newblock In Yvo~G. Desmedt, editor, {\it Proceedings CRYPTO 94}, pages~1--11,
  Springer, 1994.
\newblock Lecture Notes in Computer Science No.\ 839.

\end{thebibliography}
