diff --git a/configure.ac b/configure.ac
index f1b9a81..9c2eadc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,4 +1,4 @@
-AC_INIT([libfreefare],[0.3.4])
+AC_INIT([libfreefare],[0.3.5])
 
 AC_CONFIG_MACRO_DIR([m4])
 
@@ -58,7 +58,7 @@ AC_CHECK_LIB([crypto], [DES_ecb_encrypt], [], [AC_MSG_ERROR([Cannot find libcryp
 AC_CHECK_HEADERS([openssl/aes.h openssl/des.h openssl/rand.h], [], [AC_MSG_ERROR([Cannot find openssl headers.])])
 
 # Checks for pkg-config modules.
-LIBNFC_REQUIRED_VERSION="1.6.0"
+LIBNFC_REQUIRED_VERSION="1.7.0"
 PKG_CHECK_MODULES([LIBNFC], [libnfc >= $LIBNFC_REQUIRED_VERSION], [], [AC_MSG_ERROR([libnfc >= $LIBNFC_REQUIRED_VERSION is mandatory.])])
 
 PKG_CONFIG_REQUIRES="libnfc"
diff --git a/examples/mifare-classic-format.c b/examples/mifare-classic-format.c
index 70152e6..0a703a5 100644
--- a/examples/mifare-classic-format.c
+++ b/examples/mifare-classic-format.c
@@ -1,5 +1,6 @@
 /*-
  * Copyright (C) 2010, Romain Tartiere, Romuald Conty.
+ * Copyright (C) 2012, Romuald Conty.
  * 
  * This program is free software: you can redistribute it and/or modify it
  * under the terms of the GNU Lesser General Public License as published by the
@@ -164,15 +165,16 @@ main(int argc, char *argv[])
     nfc_connstring devices[8];
 
     size_t device_count;
-    
-    nfc_init(NULL);
 
-    device_count = nfc_list_devices (NULL, devices, 8);
+    nfc_context *context;
+    nfc_init (&context);
+
+    device_count = nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; d < device_count; d++) {
-	device = nfc_open (NULL, devices[d]);
+	device = nfc_open (context, devices[d]);
 	if (!device) {
 	    warnx ("nfc_open() failed.");
 	    error = EXIT_FAILURE;
@@ -247,6 +249,6 @@ main(int argc, char *argv[])
 	nfc_close (device);
     }
 
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 }
diff --git a/examples/mifare-classic-read-ndef.c b/examples/mifare-classic-read-ndef.c
index 1e1c1ef..891ffb9 100644
--- a/examples/mifare-classic-read-ndef.c
+++ b/examples/mifare-classic-read-ndef.c
@@ -114,15 +114,16 @@ main(int argc, char *argv[])
 
     nfc_connstring devices[8];
     size_t device_count;
-    
-    nfc_init(NULL);
 
-    device_count= nfc_list_devices (NULL, devices, 8);
+    nfc_context *context;
+    nfc_init (&context);
+
+    device_count= nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; d < device_count; d++) {
-        device = nfc_open (NULL, devices[d]);
+        device = nfc_open (context, devices[d]);
         if (!device) {
             warnx ("nfc_open() failed.");
             error = EXIT_FAILURE;
@@ -228,6 +229,6 @@ error:
 	nfc_close (device);
     }
   
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 }
diff --git a/examples/mifare-classic-write-ndef.c b/examples/mifare-classic-write-ndef.c
index 39898c6..c711c3f 100644
--- a/examples/mifare-classic-write-ndef.c
+++ b/examples/mifare-classic-write-ndef.c
@@ -195,14 +195,15 @@ main(int argc, char *argv[])
     nfc_connstring devices[8];
     size_t device_count;
     
-    nfc_init(NULL);
+    nfc_context *context;
+    nfc_init (&context);
 
-    device_count = nfc_list_devices (NULL, devices, 8);
+    device_count = nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; d < device_count; d++) {
-        device = nfc_open (NULL, devices[d]);
+        device = nfc_open (context, devices[d]);
         if (!device) {
             warnx ("nfc_open() failed.");
             error = EXIT_FAILURE;
@@ -408,6 +409,6 @@ error:
     }
 
     free (card_write_keys);
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 }
diff --git a/examples/mifare-desfire-access.c b/examples/mifare-desfire-access.c
index 36176fd..63046b9 100644
--- a/examples/mifare-desfire-access.c
+++ b/examples/mifare-desfire-access.c
@@ -40,15 +40,16 @@ main(int argc, char *argv[])
 
     nfc_connstring devices[8];
     size_t device_count;
-    
-    nfc_init(NULL);
 
-    device_count = nfc_list_devices (NULL, devices, 8);
+    nfc_context *context;
+    nfc_init (&context);
+
+    device_count = nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; d < device_count; d++) {
-        device = nfc_open (NULL, devices[d]);
+        device = nfc_open (context, devices[d]);
         if (!device) {
             warnx ("nfc_open() failed.");
             error = EXIT_FAILURE;
@@ -131,7 +132,7 @@ main(int argc, char *argv[])
 	freefare_free_tags (tags);
 	nfc_close (device);
     }
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 } /* main() */
 
diff --git a/examples/mifare-desfire-create-ndef.c b/examples/mifare-desfire-create-ndef.c
index 6b01bbc..a652da8 100644
--- a/examples/mifare-desfire-create-ndef.c
+++ b/examples/mifare-desfire-create-ndef.c
@@ -95,15 +95,16 @@ main(int argc, char *argv[])
 
     nfc_connstring devices[8];
     size_t device_count;
-    
-    nfc_init(NULL);
 
-    device_count = nfc_list_devices (NULL, devices, 8);
+    nfc_context *context;
+    nfc_init (&context);
+
+    device_count = nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; d < device_count; d++) {
-        device = nfc_open (NULL, devices[d]);
+        device = nfc_open (context, devices[d]);
         
         if (!device) {
             warnx ("nfc_open() failed.");
@@ -310,6 +311,6 @@ main(int argc, char *argv[])
 	freefare_free_tags (tags);
 	nfc_close (device);
     }
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 }
diff --git a/examples/mifare-desfire-ev1-configure-ats.c b/examples/mifare-desfire-ev1-configure-ats.c
index fb70294..1783c73 100644
--- a/examples/mifare-desfire-ev1-configure-ats.c
+++ b/examples/mifare-desfire-ev1-configure-ats.c
@@ -88,15 +88,16 @@ main(int argc, char *argv[])
 
     nfc_connstring devices[8];
     size_t device_count;
-    
-    nfc_init(NULL);
 
-    device_count = nfc_list_devices (NULL, devices, 8);
+    nfc_context *context;
+    nfc_init (&context);
+
+    device_count = nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; (!error) && (d < device_count); d++) {
-        device = nfc_open (NULL, devices[d]);
+        device = nfc_open (context, devices[d]);
         if (!device) {
             warnx ("nfc_open() failed.");
             error = EXIT_FAILURE;
@@ -174,7 +175,7 @@ main(int argc, char *argv[])
 	freefare_free_tags (tags);
 	nfc_close (device);
     }
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 } /* main() */
 
diff --git a/examples/mifare-desfire-ev1-configure-default-key.c b/examples/mifare-desfire-ev1-configure-default-key.c
index ae46a33..fa4174e 100644
--- a/examples/mifare-desfire-ev1-configure-default-key.c
+++ b/examples/mifare-desfire-ev1-configure-default-key.c
@@ -75,14 +75,15 @@ main(int argc, char *argv[])
     nfc_connstring devices[8];
     size_t device_count;
     
-    nfc_init(NULL);
+    nfc_context *context;
+    nfc_init (&context);
 
-    device_count = nfc_list_devices (NULL, devices, 8);
+    device_count = nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; (!error) && (d < device_count); d++) {
-        device = nfc_open (NULL, devices[d]);
+        device = nfc_open (context, devices[d]);
         if (!device) {
             warnx ("nfc_open() failed.");
             error = EXIT_FAILURE;
@@ -247,6 +248,6 @@ main(int argc, char *argv[])
 	freefare_free_tags (tags);
 	nfc_close (device);
     }
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 }
diff --git a/examples/mifare-desfire-ev1-configure-random-uid.c b/examples/mifare-desfire-ev1-configure-random-uid.c
index 111d851..d93d8ab 100644
--- a/examples/mifare-desfire-ev1-configure-random-uid.c
+++ b/examples/mifare-desfire-ev1-configure-random-uid.c
@@ -85,14 +85,15 @@ main(int argc, char *argv[])
     nfc_connstring devices[8];
     size_t device_count;
     
-    nfc_init(NULL);
+    nfc_context *context;
+    nfc_init (&context);
 
-    device_count = nfc_list_devices (NULL, devices, 8);
+    device_count = nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; (!error) && (d < device_count); d++) {
-        device = nfc_open (NULL, devices[d]);
+        device = nfc_open (context, devices[d]);
         if (!device) {
             warnx ("nfc_open() failed.");
             error = EXIT_FAILURE;
@@ -203,7 +204,7 @@ main(int argc, char *argv[])
 	freefare_free_tags (tags);
 	nfc_close (device);
     }
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 } /* main() */
 
diff --git a/examples/mifare-desfire-format.c b/examples/mifare-desfire-format.c
index 0889d4c..4baa5db 100644
--- a/examples/mifare-desfire-format.c
+++ b/examples/mifare-desfire-format.c
@@ -85,14 +85,15 @@ main(int argc, char *argv[])
     nfc_connstring devices[8];
     size_t device_count;
     
-    nfc_init(NULL);
+    nfc_context *context;
+    nfc_init (&context);
 
-    device_count = nfc_list_devices (NULL, devices, 8);
+    device_count = nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; (!error) && (d < device_count); d++) {
-        device = nfc_open (NULL, devices[d]);
+        device = nfc_open (context, devices[d]);
         if (!device) {
             warnx ("nfc_open() failed.");
             error = EXIT_FAILURE;
@@ -166,7 +167,7 @@ main(int argc, char *argv[])
 	freefare_free_tags (tags);
 	nfc_close (device);
     }
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 } /* main() */
 
diff --git a/examples/mifare-desfire-info.c b/examples/mifare-desfire-info.c
index c8f06b1..a2db8e2 100644
--- a/examples/mifare-desfire-info.c
+++ b/examples/mifare-desfire-info.c
@@ -39,14 +39,15 @@ main(int argc, char *argv[])
     nfc_connstring devices[8];
     size_t device_count;
     
-    nfc_init(NULL);
+    nfc_context *context;
+    nfc_init (&context);
 
-    device_count = nfc_list_devices (NULL, devices, 8);
+    device_count = nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; d < device_count; d++) {
-        device = nfc_open (NULL, devices[d]);
+        device = nfc_open (context, devices[d]);
         if (!device) {
             warnx ("nfc_open() failed.");
             error = EXIT_FAILURE;
@@ -141,7 +142,7 @@ main(int argc, char *argv[])
 	freefare_free_tags (tags);
 	nfc_close (device);
     }
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 } /* main() */
 
diff --git a/examples/mifare-desfire-read-ndef.c b/examples/mifare-desfire-read-ndef.c
index 6b9f582..f7fedd5 100644
--- a/examples/mifare-desfire-read-ndef.c
+++ b/examples/mifare-desfire-read-ndef.c
@@ -124,14 +124,15 @@ main(int argc, char *argv[])
     nfc_connstring devices[8];
     size_t device_count;
     
-    nfc_init(NULL);
+    nfc_context *context;
+    nfc_init (&context);
 
-    device_count = nfc_list_devices (NULL, devices, 8);
+    device_count = nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; d < device_count; d++) {
-        device = nfc_open (NULL, devices[d]);
+        device = nfc_open (context, devices[d]);
         
         if (!device) {
             warnx ("nfc_open() failed.");
@@ -269,6 +270,6 @@ main(int argc, char *argv[])
 	freefare_free_tags (tags);
 	nfc_close (device);
     }
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 }
diff --git a/examples/mifare-desfire-write-ndef.c b/examples/mifare-desfire-write-ndef.c
index a34ebda..0082f78 100644
--- a/examples/mifare-desfire-write-ndef.c
+++ b/examples/mifare-desfire-write-ndef.c
@@ -153,14 +153,15 @@ main(int argc, char *argv[])
     nfc_connstring devices[8];
     size_t device_count;
     
-    nfc_init(NULL);
+    nfc_context *context;
+    nfc_init (&context);
 
-    device_count = nfc_list_devices (NULL, devices, 8);
+    device_count = nfc_list_devices (context, devices, 8);
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found.");
 
     for (size_t d = 0; d < device_count; d++) {
-        device = nfc_open (NULL, devices[d]);
+        device = nfc_open (context, devices[d]);
         
         if (!device) {
             warnx ("nfc_open() failed.");
@@ -292,6 +293,6 @@ main(int argc, char *argv[])
 	freefare_free_tags (tags);
 	nfc_close (device);
     }
-    nfc_exit(NULL);
+    nfc_exit (context);
     exit (error);
 }
diff --git a/examples/mifare-ultralight-info.c b/examples/mifare-ultralight-info.c
index a191cea..f9ca9a6 100644
--- a/examples/mifare-ultralight-info.c
+++ b/examples/mifare-ultralight-info.c
@@ -36,14 +36,15 @@ main (int argc, char *argv[])
     nfc_connstring devices[8];
     size_t device_count;
 
-    nfc_init (NULL);
+    nfc_context *context;
+    nfc_init (&context);
 
-    device_count = nfc_list_devices (NULL, devices, sizeof (devices) / sizeof (*devices));
+    device_count = nfc_list_devices (context, devices, sizeof (devices) / sizeof (*devices));
     if (device_count <= 0)
 	errx (EXIT_FAILURE, "No NFC device found");
 
     for (size_t d = 0; d < device_count; d++) {
-	if (!(device = nfc_open (NULL, devices[d]))) {
+	if (!(device = nfc_open (context, devices[d]))) {
 	    warnx ("nfc_open() failed.");
 	    error = EXIT_FAILURE;
 	    continue;
@@ -85,6 +86,6 @@ main (int argc, char *argv[])
 	nfc_close (device);
     }
 
-    nfc_exit (NULL);
+    nfc_exit (context);
     exit(error);
 }