diff --git a/src/cryptography/Des.java b/src/cryptography/Des.java
index 0087589..6dcd03b 100644
--- a/src/cryptography/Des.java
+++ b/src/cryptography/Des.java
@@ -92,6 +92,24 @@ public class Des {
         System.arraycopy(newTab, 0, bloc, 0, newTab.length);
     }
 
+    public static int[][] decoupage(int[] bloc, int nbBlocs) {
+
+        if(bloc.length % nbBlocs == 0) {
+            int z = bloc.length / nbBlocs;
+            int [][] newTab = new int[nbBlocs][z];
+            int y = 0;
+
+            for (int i = 0; i < bloc.length ; i++) {
+                if (i % z == 0 && i > 0) {
+                    y++;
+                }
+                newTab[y][i - y * z] = i;
+            }
+            return newTab;
+        }
+        return null;
+    }
+
     private static int[] crypte(String message_clair) {
 //        int[] msg_crypte = message_clair.byt
         return null; // Todo Bouchon
diff --git a/src/cryptography/test/testDes.java b/src/cryptography/test/testDes.java
index df075bf..8640902 100644
--- a/src/cryptography/test/testDes.java
+++ b/src/cryptography/test/testDes.java
@@ -53,11 +53,18 @@ public class testDes {
         System.out.println(Arrays.equals(bloc, bloc2));
     }
 
+    public static void testDecoupage() {
+
+        System.out.println(Arrays.deepToString(Des.decoupage(new int[]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19}, 4)));
+
+    }
+
     public static void main(String[] args) {
         // testStringToBits();
         // testBitsToString();
         // testGenerePermutation();
         // testPermuation();
-        testInvPermuation();
+        //testInvPermuation();
+        testDecoupage();
     }
 }