diff --git a/a.exe b/a.exe
index 2333f04..435a29f 100644
Binary files a/a.exe and b/a.exe differ
diff --git a/a.exe.stackdump b/a.exe.stackdump
new file mode 100644
index 0000000..f0a3185
--- /dev/null
+++ b/a.exe.stackdump
@@ -0,0 +1,40 @@
+Exception: STATUS_INTEGER_DIVIDE_BY_ZERO at rip=0001004010E2
+rax=000000000000004F rbx=0000000A00000410 rcx=0000000A00000010
+rdx=0000000000000000 rsi=0000000A000003B0 rdi=00000007FFFFCC60
+r8 =00000007FFFFCB1C r9 =00000001800A4F70 r10=0000000800000000
+r11=000000010040115D r12=00000007FFFFCC8D r13=0000000000000000
+r14=0000000000000000 r15=00000007FFFFCC60
+rbp=00000007FFFFCC10 rsp=00000007FFFFCBB0
+program=C:\Users\benja\Documents\UPEC\decodages\a.exe, pid 1692, thread main
+cs=0033 ds=002B es=002B fs=0053 gs=002B ss=002B
+Stack trace:
+Frame         Function      Args
+0007FFFFCC10  0001004010E2 (0007FFFFCC60, 000000000000, 000000000030, 000700000000) a.exe+0x10E2
+0007FFFFCD30  000180047ED1 (000000000000, 000000000000, 000000000000, 000000000000) msys-2.0.dll+0x7ED1
+000000000000  000180045AC3 (000000000000, 000000000000, 000000000000, 000000000000) msys-2.0.dll+0x5AC3
+0007FFFFFFF0  000180045B74 (000000000000, 000000000000, 000000000000, 000000000000) msys-2.0.dll+0x5B74
+End of stack trace
+Loaded modules:
+000100400000 a.exe
+7FFC94C70000 ntdll.dll
+7FFC93430000 KERNEL32.DLL
+7FFC921F0000 KERNELBASE.dll
+000180040000 msys-2.0.dll
+7FFC93500000 advapi32.dll
+7FFC93FC0000 msvcrt.dll
+7FFC93230000 sechost.dll
+7FFC921C0000 bcrypt.dll
+7FFC94070000 RPCRT4.dll
+7FFC91740000 CRYPTBASE.DLL
+7FFC92020000 bcryptPrimitives.dll
+7FFC6FA40000 netapi32.dll
+7FFC8C9A0000 SAMCLI.DLL
+7FFC920A0000 ucrtbase.dll
+7FFC8CF20000 SAMLIB.dll
+7FFC90A00000 NETUTILS.DLL
+7FFC94190000 user32.dll
+7FFC925A0000 win32u.dll
+7FFC93C90000 GDI32.dll
+7FFC92670000 gdi32full.dll
+7FFC925D0000 msvcp_win.dll
+7FFC93960000 IMM32.DLL
diff --git a/etape3.c b/etape3.c
index e69de29..b9c3759 100644
--- a/etape3.c
+++ b/etape3.c
@@ -0,0 +1,42 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+long long int calculmodulo(long long int nb, long long int d, long long int n) {
+    long long int resultat = 1;
+
+    // Utilisation de l'algorithme d'exponentiation rapide pour gerer les grands nombres
+    while (d > 0) {
+        // Si le bit de droite de d est 1 (d est impair)
+        if (d % 2 == 1) {
+            resultat = (resultat * nb) % n;  // Multiplier le resultat par nb et prendre le modulo n
+        }
+
+        d = d / 2;          // Diviser d par 2 (decalage d'octets vers la droite)
+        nb = (nb * nb) % n; // elever nb au carre et prendre le modulo n
+
+        // Lignes ajoutées pour illustrer le processus
+        printf("d = %lld, nb = %lld, resultat = %lld\n", d, nb, resultat);
+    }
+
+    return resultat;
+}
+
+int main(void) {
+    /*Parametres RSA*/
+    long long n = 6554179;
+    long long e = 689149;
+    long long d = 55621;
+
+    FILE* stream = fopen("Etape4.bin","r");
+
+    /*Variable pour caracteres*/
+    long long int nb;
+    /*Tant que la fin du fichier n'est pas atteinte, dechiffrer chaque caractere*/
+    /*en calculant le modulo de la valeur numerique de chacun*/
+    while (fread(&nb, sizeof(long long int), 1, stream) != 0) {
+        long long int dechiffre = calculmodulo(nb, d, n);
+        printf("%c", (char)dechiffre);
+    }
+    fclose(stream);
+}
\ No newline at end of file