diff --git a/src/mfoc.c b/src/mfoc.c
index e2545be..18d7890 100644
--- a/src/mfoc.c
+++ b/src/mfoc.c
@@ -96,17 +96,17 @@ int main(int argc, char *const argv[])
   uint8_t defaultKeys[][6] = {
     {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}, // Default key (first key used by program if no user defined key)
     {0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5}, // NFCForum MAD key
-    {0xd3, 0xf7, 0xd3, 0xf7, 0xd3, 0xf7}, // NFCForum content key
-    {0x00, 0x00, 0x00, 0x00, 0x00, 0x00}, // Blank key
-    {0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5},
-    {0x4d, 0x3a, 0x99, 0xc3, 0x51, 0xdd},
-    {0x1a, 0x98, 0x2c, 0x7e, 0x45, 0x9a},
-    {0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff},
-    {0x71, 0x4c, 0x5c, 0x88, 0x6e, 0x97},
-    {0x58, 0x7e, 0xe5, 0xf9, 0x35, 0x0f},
-    {0xa0, 0x47, 0x8c, 0xc3, 0x90, 0x91},
-    {0x53, 0x3c, 0xb6, 0xc7, 0x23, 0xf6},
-    {0x8f, 0xd0, 0xa4, 0xf2, 0x56, 0xe9}
+//    {0xd3, 0xf7, 0xd3, 0xf7, 0xd3, 0xf7}, // NFCForum content key
+//    {0x00, 0x00, 0x00, 0x00, 0x00, 0x00}, // Blank key
+//    {0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5},
+//    {0x4d, 0x3a, 0x99, 0xc3, 0x51, 0xdd},
+//    {0x1a, 0x98, 0x2c, 0x7e, 0x45, 0x9a},
+//    {0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff},
+//    {0x71, 0x4c, 0x5c, 0x88, 0x6e, 0x97},
+//    {0x58, 0x7e, 0xe5, 0xf9, 0x35, 0x0f},
+//    {0xa0, 0x47, 0x8c, 0xc3, 0x90, 0x91},
+//    {0x53, 0x3c, 0xb6, 0xc7, 0x23, 0xf6},
+//    {0x8f, 0xd0, 0xa4, 0xf2, 0x56, 0xe9}
 
   };
 
@@ -143,7 +143,8 @@ int main(int argc, char *const argv[])
     switch (ch) {
       case 'P':
         // Number of probes
-        if (!(probes = atoi(optarg)) || probes < 1) {
+        probes = atoi(optarg);
+        if (probes < 0) {
           ERR("The number of probes must be a positive number");
           exit(EXIT_FAILURE);
         }
@@ -1059,7 +1060,7 @@ int mf_enhanced_auth(int e_sector, int a_sector, mftag t, mfreader r, denonce *d
       NtLast = bytes_to_num(Rx, 4) ^ crypto1_word(pcs, bytes_to_num(Rx, 4) ^ t.authuid, 1);
 
       // Make sure the card is using the known PRNG
-      if (! validate_prng_nonce(NtLast)) {
+      if (true || ! validate_prng_nonce(NtLast)) {
            printf("Card is not vulnerable to nested attack\n");
            return -99999;
       }
diff --git a/src/mfoc.h b/src/mfoc.h
index 9ea7547..8ee064b 100644
--- a/src/mfoc.h
+++ b/src/mfoc.h
@@ -30,7 +30,7 @@
 #define DEFAULT_DIST_NR         15
 
 // Default number of probes for a key recovery for one sector
-#define DEFAULT_PROBES_NR       150
+#define DEFAULT_PROBES_NR       1
 
 // Number of sets with 32b keys
 #define DEFAULT_SETS_NR         5