diff --git a/Makefile b/Makefile
index 9378403..219c2c3 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ SPECVERSION="3.3.1"
 
 APPVERSION_M=1
 APPVERSION_N=2
-APPVERSION_P=1
+APPVERSION_P=0
 APPVERSION=$(APPVERSION_M).$(APPVERSION_N).$(APPVERSION_P)
 
 ifeq ($(TARGET_NAME),TARGET_BLUE)
diff --git a/doc/user/blue-app-openpgp-card.rst b/doc/user/blue-app-openpgp-card.rst
index 97a778d..6ff16dd 100644
--- a/doc/user/blue-app-openpgp-card.rst
+++ b/doc/user/blue-app-openpgp-card.rst
@@ -96,7 +96,15 @@ The application is ready to use!
 From source
 ~~~~~~~~~~~~~
 
-Building from sources requires the the Nano S SDK 1.4.2.1 on firmware 1.4.2. See https://github.com/LedgerHQ/nanos-secure-sdk
+Building from sources requires the the Nano S SDK 1.3.1.4 on firmware 1.3.1. See https://github.com/LedgerHQ/nanos-secure-sdk
+
+The SDK must be slightly modified:
+
+   - replace lib_stusb/STM32_USB_Device_Library/Class/CCID/src/usbd_ccid_if.c
+     and lib_stusb/STM32_USB_Device_Library/Class/CCID/inc/usbd_ccid_if.h by the 
+     one provided in sdk/ directory
+   - edit script.ld and modify the stack size : STACK_SIZE = 832;
+
 
 Refer to the SDK documentation for the compiling/loading...
 
diff --git a/pytools/gpgcard/restore_perso.py b/pytools/gpgcard/restore_perso.py
deleted file mode 100644
index 9c20560..0000000
--- a/pytools/gpgcard/restore_perso.py
+++ /dev/null
@@ -1,35 +0,0 @@
-import binascii
-
-from gpgcard import GPGCard
-
-print("Connecting to device ...")
-gpgcard = GPGCard()
-gpgcard.connect("pcsc:Ledger")
-gpgcard.get_all()
-
-gpgcard.verify_pin(0x81, "123456")
-gpgcard.verify_pin(0x83, "12345678")
-
-print("Generating key 1/3 ...")
-gpgcard.generate_asym_key_pair(0x80, 0xb600)
-print("Generating key 2/3 ...")
-gpgcard.generate_asym_key_pair(0x80, 0xb800)
-print("Generating key 3/3 ...")
-gpgcard.generate_asym_key_pair(0x80, 0xa400)
-
-# Use 'gpg -k --with-subkey-fingerprint' to find fingerprints
-
-print("Setting fingerprints ...")
-sig_fingerprint = b'A3F35A5124D47C3195FF07B7F85D93686A3A9063'
-aut_fingerprint = b'9C686F97A39B4A34E0C9D37CDBF45893AB524BBC'
-dec_fingerprint = b'E4FE54969060DBF2756FC0EFD8203245E390CAEA'
-
-sig_fingerprint_bin = binascii.unhexlify(sig_fingerprint)
-aut_fingerprint_bin = binascii.unhexlify(aut_fingerprint)
-dec_fingerprint_bin = binascii.unhexlify(dec_fingerprint)
-
-gpgcard.sig_fingerprints = sig_fingerprint_bin
-gpgcard.aut_fingerprints = aut_fingerprint_bin
-gpgcard.dec_fingerprints = dec_fingerprint_bin
-
-gpgcard.set_all() 
diff --git a/src/gpg_pso.c b/src/gpg_pso.c
index 1d389b0..8d1895c 100644
--- a/src/gpg_pso.c
+++ b/src/gpg_pso.c
@@ -88,9 +88,7 @@ static int gpg_sign(gpg_key_t *sigkey) {
       unsigned char *rs;
 
       key = &sigkey->priv_key.ecfp;
-
       //sign
-      #define RS (G_gpg_vstate.work.io_buffer+(GPG_IO_BUFFER_LENGTH-256))
       if (sigkey->attributes.value[0] == 19) {
         sz = gpg_curve2domainlen(key->curve);
         if ((sz == 0) || (key->d_len != sz)) {
@@ -101,13 +99,13 @@ static int gpg_sign(gpg_key_t *sigkey) {
                            CX_RND_TRNG,
                            CX_NONE,
                            G_gpg_vstate.work.io_buffer, sz,
-                           RS, 256,
+                           G_gpg_vstate.work.io_buffer, GPG_IO_BUFFER_LENGTH,
                            NULL);
         //reencode r,s in MPI format
         gpg_io_discard(0);
       
-        rs_len =  RS[3];
-        rs     =  &RS[4];
+        rs_len =  G_gpg_vstate.work.io_buffer[3];
+        rs     =  &G_gpg_vstate.work.io_buffer[4];
       
         for (i = 0; i<2; i++) {
           if (*rs == 0) {
@@ -126,13 +124,12 @@ static int gpg_sign(gpg_key_t *sigkey) {
                            CX_SHA512, 
                            G_gpg_vstate.work.io_buffer, G_gpg_vstate.io_length,
                            NULL, 0,
-                           RS, 256,
+                           G_gpg_vstate.work.io_buffer+128, GPG_IO_BUFFER_LENGTH-128,
                            NULL);
         gpg_io_discard(0);
-        gpg_io_insert(RS, sz);
+        gpg_io_insert(G_gpg_vstate.work.io_buffer+128, sz);
       }
-      #undef RS
-
+      
       //send
       gpg_pso_reset_PW1();
       return SW_OK;