diff --git a/src/device/device.hpp b/src/device/device.hpp
index 91bc30c53..9df0cb39d 100644
--- a/src/device/device.hpp
+++ b/src/device/device.hpp
@@ -78,6 +78,7 @@ namespace hw {
            return false;
     }
 
+
     class device {
     protected:
         std::string  name;
@@ -89,10 +90,12 @@ namespace hw {
         virtual ~device()   {}
 
         explicit virtual operator bool() const = 0;
-
-        static const int SIGNATURE_REAL = 0;
-        static const int SIGNATURE_FAKE = 1;
-
+        enum device_mode {
+            NONE,
+            TRANSACTION_CREATE_REAL,
+            TRANSACTION_CREATE_FAKE,
+            TRANSACTION_PARSE
+        };
 
         /* ======================================================================= */
         /*                              SETUP/TEARDOWN                             */
@@ -106,6 +109,9 @@ namespace hw {
         virtual bool connect(void) = 0;
         virtual bool disconnect(void) = 0;
 
+        virtual bool  set_mode(device_mode mode) = 0;
+
+
         /* ======================================================================= */
         /*  LOCKER                                                                 */
         /* ======================================================================= */ 
diff --git a/src/device/device_default.cpp b/src/device/device_default.cpp
index 3f7b8078d..0071f7d4f 100644
--- a/src/device/device_default.cpp
+++ b/src/device/device_default.cpp
@@ -82,6 +82,9 @@ namespace hw {
             dfns();
         }
 
+        bool  device_default::set_mode(device_mode mode) {
+            return true;
+        }
 
         /* ======================================================================= */
         /*  LOCKER                                                                 */
diff --git a/src/device/device_ledger.cpp b/src/device/device_ledger.cpp
index c919c4ac1..6fdb6bb1c 100644
--- a/src/device/device_ledger.cpp
+++ b/src/device/device_ledger.cpp
@@ -511,12 +511,13 @@ namespace hw {
         return true;
     }
 
-    bool  device_ledger::get_secret_keys(crypto::secret_key &viewkey , crypto::secret_key &spendkey) {
+    bool  device_ledger::get_secret_keys(crypto::secret_key &vkey , crypto::secret_key &skey) {
         AUTO_LOCK_CMD();
-      memset(viewkey.data, 0x00, 32);
-      memset(spendkey.data, 0xFF, 32);
 
-      #ifdef DEBUG_HWDEVICE
+        //secret key are represented as fake key on the wallet side
+        memset(vkey.data, 0x00, 32);
+        memset(skey.data, 0xFF, 32);
+
         //spcialkey, normal conf handled in decrypt
         int offset;
         reset_buffer();
@@ -535,12 +536,22 @@ namespace hw {
         this->length_send = offset;
         this->exchange();
 
-        //clear key
-        memmove(ledger::viewkey.data,  this->buffer_recv+64, 32);
-        memmove(ledger::spendkey.data, this->buffer_recv+96, 32);
+        //View key is retrievied, if allowed, to speed up blockchain parsing
+        memmove(this->viewkey.data,  this->buffer_recv+0,  32);
+        if (is_fake_view_key(this->viewkey)) {
+          MDEBUG("Have Not view key");
+          this->has_view_key = false;
+        } else {
+          MDEBUG("Have view key");
+          this->has_view_key = true;
+        }
+      
+        #ifdef DEBUG_HWDEVICE
+        memmove(dbg_viewkey.data, this->buffer_recv+0, 32);
+        memmove(dbg_spendkey.data, this->buffer_recv+32, 32);
+        #endif
 
-      #endif
-      return true;
+        return true;
     }
 
     bool  device_ledger::generate_chacha_key(const cryptonote::account_keys &keys, crypto::chacha_key &key) {
@@ -585,8 +596,6 @@ namespace hw {
 
     bool device_ledger::derive_subaddress_public_key(const crypto::public_key &pub, const crypto::key_derivation &derivation, const std::size_t output_index, crypto::public_key &derived_pub){
         AUTO_LOCK_CMD();
-        int offset;
-
         #ifdef DEBUG_HWDEVICE
         const crypto::public_key pub_x = pub;
         crypto::key_derivation derivation_x;
@@ -643,10 +652,10 @@ namespace hw {
 
         //pub key
         memmove(derived_pub.data, &this->buffer_recv[0], 32);
-
-        #ifdef DEBUG_HWDEVICE
-        hw::ledger::check32("derive_subaddress_public_key", "derived_pub", derived_pub_x.data, derived_pub.data);
-        #endif
+      }
+      #ifdef DEBUG_HWDEVICE
+      hw::ledger::check32("derive_subaddress_public_key", "derived_pub", derived_pub_x.data, derived_pub.data);
+      #endif
 
       return true;
     }
@@ -1033,7 +1042,7 @@ namespace hw {
 
     bool device_ledger::generate_key_derivation(const crypto::public_key &pub, const crypto::secret_key &sec, crypto::key_derivation &derivation) {
         AUTO_LOCK_CMD();
-        int offset;
+        bool r = false;
 
         #ifdef DEBUG_HWDEVICE
         const crypto::public_key pub_x = pub;
@@ -1095,10 +1104,6 @@ namespace hw {
       return r;
     }
 
-
-      return true;
-    }
-
     bool device_ledger::derivation_to_scalar(const crypto::key_derivation &derivation, const size_t output_index, crypto::ec_scalar &res) {
         AUTO_LOCK_CMD();
         int offset;
@@ -1384,32 +1389,6 @@ namespace hw {
         return true;
     }
 
-    bool  device_ledger::set_signature_mode(unsigned int sig_mode) {
-        AUTO_LOCK_CMD();
-        int offset ;
-
-        reset_buffer();
-
-        this->buffer_send[0] = 0x00;
-        this->buffer_send[1] = INS_SET_SIGNATURE_MODE;
-        this->buffer_send[2] = 0x01;
-        this->buffer_send[3] = 0x00;
-        this->buffer_send[4] = 0x00;
-        offset = 5;
-        //options
-        this->buffer_send[offset] = 0x00;
-        offset += 1;
-        //account
-        this->buffer_send[offset] = sig_mode;
-        offset += 1;
-
-        this->buffer_send[4] = offset-5;
-        this->length_send = offset;
-        this->exchange();
-        
-      return true;
-    }
-
     bool device_ledger::encrypt_payment_id(crypto::hash8 &payment_id, const crypto::public_key &public_key, const crypto::secret_key &secret_key) {
         AUTO_LOCK_CMD();
         int offset;
diff --git a/src/device/device_ledger.hpp b/src/device/device_ledger.hpp
index 90907616f..e29fa7cce 100644
--- a/src/device/device_ledger.hpp
+++ b/src/device/device_ledger.hpp
@@ -138,6 +138,7 @@ namespace hw {
         bool connect(void) override;
         bool disconnect() override;
 
+        bool  set_mode(device_mode mode) override;
 
         /* ======================================================================= */
         /*  LOCKER                                                                 */