\begin{tikzpicture}

    \def \h{-2}

    %Donnée utilisateur
    \node[color=gray] (ludata) at (0,1) {Donnée utilisateur};
    \node (udata) at (0,-0.36) {};
    \draw[color=gray] (-4,0.5) rectangle (4,-0.5);
    \node[rectangle,draw] (x) at (-2,0) {Donnée d'entrée};
    \node[rectangle,draw] (s) at (2,0) {Attribut sensible};

    %Modèle cible
    \draw[color=gray] (-4.5,\h+0.5) rectangle (1.5,\h-2);
    \node[color=gray] (lmcible) at (-1.5,\h-2.5) {Modèle cible};

    %Pipeline
    \node[rectangle,draw=blue] (model) at (0,\h) {Modèle};
    \node[rectangle,draw] (inf) at (0,\h-1) {Classification};
    \node[rectangle,draw=red] (train) at (-3,\h) {Entrainement};

    \draw[->] (udata) to (model);
    \draw[->] (model) to (inf);
    \draw[->] (train) to (model);

    %Attaque
    \node[rectangle,draw=blue] (att) at (5,\h) {Attaque};

    %\draw[->,color=blue] (x) to (att);
    %\draw[->,color=blue] (model) to (att);
    \draw[->,color=blue] (model) to (att);
    \draw[->,color=red] (att) to [bend right] (train);


    %\draw[color=red] (-2,0.5) rectangle (2,-0.5);
    %\node[color=red] (cible) at (0,1) {Cible de l'attaque};
\end{tikzpicture}