From: Jean-François Couchot <couchot@couchot.iut-bm.univ-fcomte.fr>
Date: Fri, 17 Jul 2015 11:10:25 +0000 (+0200)
Subject: ajout preuve chaos
X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/hdrcouchot.git/commitdiff_plain/35f9a1f25d6fb4d3d2993aa5d75b474742eb8ac6?ds=sidebyside;hp=2bf0bca226facdce323e96552021bf90952eefce

ajout preuve chaos
---

diff --git a/15RairoGen.tex b/15RairoGen.tex
index aff664f..4c9a25b 100644
--- a/15RairoGen.tex
+++ b/15RairoGen.tex
@@ -146,8 +146,8 @@ et $h(x_1,x_2)=(\overline{x_1},x_1\overline{x_2}+\overline{x_1}x_2)$.
 Leurs graphes d'interactions donnés en figure \ref{fig:g:inter} et \ref{fig:h:inter}
 vérifient les hypothèses du théorème~\ref{th:Adrien}. 
 Leurs graphes d'itérations
-sont donc fortement connexes, ce que l'on peut vérifier aux figures
-\ref{fig:g:iter} et \ref{fig:h:iter}.
+sont donc fortement connexes, ce que l'on peut vérifier aux figures~\ref{fig:g:iter} 
+et~\ref{fig:h:iter}.
 \textit{A priori}, ces deux fonctions pourraient être intégrées
 dans un générateur de nombres pseudo aléatoires. Montrons que ce n'est pas le cas pour $g$ et 
 que cela l'est pour $h$.
@@ -648,5 +648,86 @@ $d$ est une distance sur $\mathcal{X}_{\mathsf{N},\mathcal{P}}$.
 
 \subsection{Le graphe $\textsc{giu}_{\mathcal{P}}(f)$ étendant  $\textsc{giu}(f)$}
 
+A partir de  $\mathcal{P}=\{p_1, p_2, \hdots, p_\mathsf{p}\}$, on 
+definit le graphe orienté $\textsc{giu}_{\mathcal{P}}(f)$ de la manière suivante:
+\begin{itemize}
+\item les n{\oe}uds sont les  $2^\mathsf{N}$ configurations de $\mathds{B}^\mathsf{N}$,
+%\item Each vertex has $\displaystyle{\sum_{i=1}^\mathsf{p} \mathsf{N}^{p_i}}$ arrows, namely all the $p_1, p_2, \hdots, p_\mathsf{p}$ tuples 
+%  having their elements in $\llbracket 1, \mathsf{N} \rrbracket $.
+\item il y a un arc libellé $u_0, \hdots, u_{p_i-1}$, $i \in \llbracket 1, \mathsf{p} \rrbracket$ entre les n{\oe}uds $x$ et $y$ si et seulement si $p_i$ est un élément de 
+$\mathcal{P}$ (\textit{i.e.}, on peut itérer $p_i$ fois), 
+chaque $u_k$ de la suite appartient à $[\mathsf{N}]$ et 
+$y=F_{f_u,p_i} (x, (u_0, \hdots, u_{p_i-1})) $.
+\end{itemize}
+Il n'est pas difficile de constater que $\textsc{giu}_{\{1\}}(f)$ est $\textsc{giu}(f)$.
+
+
+
+
+
+\begin{figure}%[t]
+  \begin{center}
+    \subfigure[$\textsc{giu}_{\{2\}}(h)$]{
+      \begin{minipage}{0.30\textwidth}
+        \begin{center}
+          \includegraphics[height=4cm]{images/h2prng.pdf}
+        \end{center}
+      \end{minipage}
+      \label{fig:h2prng}
+    }
+    \subfigure[$\textsc{giu}_{\{3\}}(h)$]{
+      \begin{minipage}{0.40\textwidth}
+        \begin{center}
+          \includegraphics[height=4cm]{images/h3prng.pdf}
+        \end{center}
+      \end{minipage}
+      \label{fig:h3prng}
+    }
+    \subfigure[$\textsc{giu}_{\{2,3\}}(h)$]{
+      \begin{minipage}{0.40\textwidth}
+        \begin{center}
+          \includegraphics[height=4cm]{images/h23prng.pdf}
+        \end{center}
+      \end{minipage}
+      \label{fig:h23prng}
+    }
+
+    \end{center}
+    \caption{Graphes d'iterations $\textsc{giu}_{\mathcal{P}}(h)$ pour $h(x_1,x_2)=(\overline{x_1},x_1\overline{x_2}+\overline{x_1}x_2)$}
+    \label{fig:xplgraphIter}
+  \end{figure}
+
+
+
+
+\begin{xpl}
+On reprend l'exemple où $\mathsf{N}=2$ et 
+$h(x_1,x_2)=(\overline{x_1},x_1\overline{x_2}+\overline{x_1}x_2)$ déjà détaillé 
+à la section~\ref{sub:prng:unif}.
+
+Le graphe $\textsc{giu}_{\{1\}}(h)$ a déjà été donné à la figure~\ref{fig:h:iter}.
+Les graphes $\textsc{giu}_{\{2\}}(h)$, $\textsc{giu}_{\{3\}}(h)$  et
+$\textsc{giu}_{\{2,3\}}(h)$ sont respectivement donnés aux figure~\ref{fig:h2prng}, ~\ref{fig:h3prng} et ~\ref{fig:h23prng}. 
+Le premier (repsectivement le second) 
+illustre le comportement du générateur lorsque qu'on itère exactement 
+2 fois (resp. 3 fois) puis qu'on affiche le résultat.
+Le dernier donnerait le comportement d'un générateur qui s'autoriserait 
+à itérer en interne systématiquement 2 ou trois fois avant de retourner un résultat.
+
+\end{xpl}
+
+
 \subsection{le PRNG de l'algorithme~\ref{CI Algorithm} est chaotique sur $\mathcal{X}_{\mathsf{N},\mathcal{P}}$}
 
+Le théorème suivant, similaire à celui dans $\mathcal{X}_u$ et dans $\mathcal{X}_g$
+est prouvé en annexes~\ref{}.
+
+\begin{theorem}
+La fonction $G_{f_u,\mathcal{P}}$ est chaotique sur 
+ $(\mathcal{X}_{\mathsf{N},\mathcal{P}},d)$ si et seulement si 
+graphe d'itération $\textsc{giu}_{\mathcal{P}}(f)$ 
+est fortement connexe.
+\end{theorem}
+
+
+
diff --git a/annexePreuveDistribution.tex b/annexePreuveDistribution.tex
index 8de466c..878b317 100644
--- a/annexePreuveDistribution.tex
+++ b/annexePreuveDistribution.tex
@@ -85,3 +85,97 @@ et en vérifiant tous les  $n \times \max{(\mathcal{P})}$ blocs, $u=\check{u}$.
 aussi.
  \end{itemize}
 \end{proof}
+
+
+
+\begin{theorem}
+La fonction $G_{f_u,\mathcal{P}}$ est chaotique sur 
+ $(\mathcal{X}_{\mathsf{N},\mathcal{P}},d)$ si et seulement si 
+graphe d'itération $\textsc{giu}_{\mathcal{P}}(f)$ 
+est fortement connexe.
+\end{theorem}
+
+\begin{proof}
+Suppose that $\Gamma_{\mathcal{P}}(f)$ is strongly connected. 
+Let $x=(e,(u,v)),\check{x}=(\check{e},(\check{u},\check{v})) 
+\in \mathcal{X}_{\mathsf{N},\mathcal{P}}$ and $\varepsilon >0$.
+We will find a point $y$ in the open ball $\mathcal{B}(x,\varepsilon )$ and
+$n_0 \in \mathds{N}$ such that $G_f^{n_0}(y)=\check{x}$: this strong transitivity
+will imply the transitivity property.
+We can suppose that $\varepsilon <1$ without loss of generality. 
+
+Let us denote by $(E,(U,V))$  the elements of $y$. As
+$y$ must be in $\mathcal{B}(x,\varepsilon)$ and  $\varepsilon < 1$,
+$E$ must be equal to $e$. Let $k=\lfloor \log_{10} (\varepsilon) \rfloor +1$.
+$d_{\mathds{S}_{\mathsf{N},\mathcal{P}}}((u,v),(U,V))$ must be lower than
+$\varepsilon$, so the $k$ first digits of the fractional part of 
+$d_{\mathds{S}_{\mathsf{N},\mathcal{P}}}((u,v),(U,V))$ are null.
+Let $k_1$ the smallest integer such that, if $V^0=v^0$, ...,  $V^{k_1}=v^{k_1}$,
+ $U^0=u^0$, ..., $U^{\sum_{l=0}^{k_1}V^l-1} = u^{\sum_{l=0}^{k_1}v^l-1}$.
+Then $d_{\mathds{S}_{\mathsf{N},\mathcal{P}}}((u,v),(U,V))<\varepsilon$.
+In other words, any $y$ of the form $(e,((u^0, ..., u^{\sum_{l=0}^{k_1}v^l-1}),
+(v^0, ..., v^{k_1}))$ is in $\mathcal{B}(x,\varepsilon)$.
+
+Let $y^0$ such a point and $z=G_f^{k_1}(y^0) = (e',(u',v'))$. $\Gamma_{\mathcal{P}}(f)$
+being strongly connected, there is a path between $e'$ and $\check{e}$. Denote
+by $a_0, \hdots, a_{k_2}$ the edges visited by this path. We denote by
+$V^{k_1}=|a_0|$ (number of terms in the finite sequence $a_1$),
+$V^{k_1+1}=|a_1|$, ..., $V^{k_1+k_2}=|a_{k_2}|$, and by 
+$U^{k_1}=a_0^0$, $U^{k_1+1}=a_0^1$, ..., $U^{k_1+V_{k_1}-1}=a_0^{V_{k_1}-1}$,
+$U^{k_1+V_{k_1}}=a_1^{0}$, $U^{k_1+V_{k_1}+1}=a_1^{1}$,...
+
+Let $y=(e,((u^0, ..., u^{\sum_{l=0}^{k_1}v^l-1}, a_0^0, ..., a_0^{|a_0|}, a_1^0, ..., a_1^{|a_1|},..., 
+ a_{k_2}^0, ..., a_{k_2}^{|a_{k_2}|},$ \linebreak
+ $\check{u}^0, \check{u}^1, ...),(v^0, ..., v^{k_1},|a_0|, ...,
+ |a_{k_2}|,\check{v}^0, \check{v}^1, ...)))$. So $y\in \mathcal{B}(x,\varepsilon)$
+ and $G_{f}^{k_1+k_2}(y)=\check{x}$.
+ 
+ 
+Conversely, if $\Gamma_{\mathcal{P}}(f)$ is not strongly connected, then there are 
+2 vertices $e_1$ and $e_2$ such that there is no path between $e_1$ and $e_2$.
+That is, it is impossible to find $(u,v)\in \mathds{S}_{\mathsf{N},\mathcal{P}}$
+and $n \mathds{N}$ such that $G_f^n(e,(u,v))_1=e_2$. The open ball $\mathcal{B}(e_2, 1/2)$
+cannot be reached from any neighborhood of $e_1$, and thus $G_f$ is not transitive.
+\end{proof}
+
+
+We show now that,
+\begin{prpstn}
+If $\Gamma_{\mathcal{P}}(f)$ is strongly connected, then $G_f$ is 
+regular on $(\mathcal{X}_{\mathsf{N},\mathcal{P}}, d)$.
+\end{prpstn}
+
+\begin{proof}
+Let $x=(e,(u,v)) \in \mathcal{X}_{\mathsf{N},\mathcal{P}}$ and $\varepsilon >0$. 
+As in the proofs of Prop.~\ref{prop:trans}, let $k_1 \in \mathds{N}$ such
+that 
+$$\left\{(e, ((u^0, ..., u^{v^{k_1-1}},U^0, U^1, ...),(v^0, ..., v^{k_1},V^0, V^1, ...)) \mid \right.$$
+$$\left.\forall i,j \in \mathds{N}, U^i \in \llbracket 1, \mathsf{N} \rrbracket, V^j \in \mathcal{P}\right\}
+\subset \mathcal{B}(x,\varepsilon),$$
+and $y=G_f^{k_1}(e,(u,v))$. $\Gamma_{\mathcal{P}}(f)$ being strongly connected,
+there is at least a path from the Boolean state $y_1$ of $y$ and $e$.
+Denote by $a_0, \hdots, a_{k_2}$ the edges of such a path.
+Then the point:
+$$(e,((u^0, ..., u^{v^{k_1-1}},a_0^0, ..., a_0^{|a_0|}, a_1^0, ..., a_1^{|a_1|},..., 
+ a_{k_2}^0, ..., a_{k_2}^{|a_{k_2}|},u^0, ..., u^{v^{k_1-1}},$$
+$$a_0^0, ...,a_{k_2}^{|a_{k_2}|}...),(v^0, ..., v^{k_1}, |a_0|, ..., |a_{k_2}|,v^0, ..., v^{k_1}, |a_0|, ..., |a_{k_2}|,...))$$
+is a periodic point in the neighborhood $\mathcal{B}(x,\varepsilon)$ of $x$.
+\end{proof}
+
+$G_f$ being topologically transitive and regular, we can thus conclude that
+\begin{thrm}
+The function $G_f$ is chaotic on $(\mathcal{X}_{\mathsf{N},\mathcal{P}},d)$ if
+and only if its iteration graph $\Gamma_{\mathcal{P}}(f)$ is strongly connected.
+\end{thrm}
+
+\begin{crllr}
+  The pseudorandom number generator $\chi_{\textit{14Secrypt}}$ is not chaotic
+  on $(\mathcal{X}_{\mathsf{N},\{b\}},d)$ for the negation function.
+\end{crllr}
+\begin{proof}
+  In this context, $\mathcal{P}$ is the singleton $\{b\}$.
+  If $b$ is even, any vertex $e$ of $\Gamma_{\{b\}}(f_0)$ cannot reach 
+  its neighborhood and thus $\Gamma_{\{b\}}(f_0)$ is not strongly connected. 
+  If $b$ is even, any vertex $e$ of $\Gamma_{\{b\}}(f_0)$ cannot reach itself 
+  and thus $\Gamma_{\{b\}}(f_0)$ is not strongly connected.
+\end{proof}
diff --git a/images/h23prng.dot b/images/h23prng.dot
new file mode 100644
index 0000000..1605403
--- /dev/null
+++ b/images/h23prng.dot
@@ -0,0 +1,21 @@
+digraph {
+ 00 -> 00 [label="11,22,112,211,222"]
+ 00 -> 10 [label="21,111,122,221"]
+ 00 -> 11 [label="12,212"]
+ 01 -> 01 [label="11,22,112,211,222"]
+ 01 -> 10 [label="12,212"]
+ 01 -> 11 [label="21,111,122,221"]
+ 10 -> 00 [label="12,111,122,221"]
+ 10 -> 01 [label="21,212"]
+ 10 -> 10 [label="11,22,121"]
+ 11 -> 00 [label="21,212"]
+ 11 -> 01 [label="12,111,122,221"]
+ 11 -> 11 [label="11,22,121"]
+
+ 00 -> 01 [label="121"]
+ 01 -> 00 [label="121"]
+ 10 -> 11 [label="112,211,222"]
+ 11 -> 10 [label="112,211,222"]
+
+ 
+}
diff --git a/images/h2prng.dot b/images/h2prng.dot
new file mode 100644
index 0000000..bc3fe76
--- /dev/null
+++ b/images/h2prng.dot
@@ -0,0 +1,15 @@
+digraph {
+ 00 -> 00 [label="11,22"]
+ 00 -> 10 [label="21"]
+ 00 -> 11 [label="12"]
+ 01 -> 01 [label="11,22"]
+ 01 -> 10 [label="12"]
+ 01 -> 11 [label="21"]
+ 10 -> 00 [label="12"]
+ 10 -> 01 [label="21"]
+ 10 -> 10 [label="11,22"]
+ 11 -> 00 [label="21"]
+ 11 -> 01 [label="12"]
+ 11 -> 11 [label="11,22"]
+
+}
diff --git a/images/h3prng.dot b/images/h3prng.dot
new file mode 100644
index 0000000..f911ba5
--- /dev/null
+++ b/images/h3prng.dot
@@ -0,0 +1,21 @@
+digraph {
+ 00 -> 00 [label="112,211,222"]
+ 00 -> 10 [label="111,122,221"]
+ 00 -> 11 [label="212"]
+ 01 -> 01 [label="112,211,222"]
+ 01 -> 10 [label="212"]
+ 01 -> 11 [label="111,122,221"]
+ 10 -> 00 [label="111,122,221"]
+ 10 -> 01 [label="212"]
+ 10 -> 10 [label="121"]
+ 11 -> 00 [label="212"]
+ 11 -> 01 [label="111,122,221"]
+ 11 -> 11 [label="121"]
+
+ 00 -> 01 [label="121"]
+ 01 -> 00 [label="121"]
+ 10 -> 11 [label="112,211,222"]
+ 11 -> 10 [label="112,211,222"]
+
+ 
+}