diff --git a/ble/att.h b/ble/att.h
index 3327da71f..362cf033c 100644
--- a/ble/att.h
+++ b/ble/att.h
@@ -81,12 +81,23 @@ extern "C" {
 #define ATT_SIGNED_WRITE_COMAND         0xD2
 
 // MARK: ATT Error Codes
-#define ATT_ERROR_ATTRIBUTE_INVALID      0x01
-#define ATT_ERROR_READ_NOT_PERMITTED     0x02
-#define ATT_ERROR_WRITE_NOT_PERMITTED    0x03
-#define ATT_ERROR_INVALID_OFFSET         0x07
-#define ATT_ERROR_ATTRIBUTE_NOT_FOUND    0x0a
-#define ATT_ERROR_UNSUPPORTED_GROUP_TYPE 0x10
+#define ATT_ERROR_ATTRIBUTE_INVALID                0x01
+#define ATT_ERROR_READ_NOT_PERMITTED               0x02
+#define ATT_ERROR_WRITE_NOT_PERMITTED              0x03
+#define ATT_ERROR_INVALID_PDU                      0x04  
+#define ATT_ERROR_INSUFFICIENT_AUTHENTICATION      0x05
+#define ATT_ERROR_REQUEST_NOT_SUPPORTED            0x06
+#define ATT_ERROR_INVALID_OFFSET                   0x07
+#define ATT_ERROR_INSUFFICIENT_AUTHORIZATION       0x08
+#define ATT_ERROR_PREPARE_QUEUE_FULL               0x09
+#define ATT_ERROR_ATTRIBUTE_NOT_FOUND              0x0a
+#define ATT_ERROR_ATTRIBUTE_NOT_LONG               0x0b
+#define ATT_ERROR_INSUFFICIENT_ENCRYPTION_KEY_SIZE 0x0c
+#define ATT_ERROR_INVALID_ATTRIBUTE_VALUE_LENGTH   0x0d
+#define ATT_ERROR_UNLIKELY_ERROR                   0x0e
+#define ATT_ERROR_INSUFFICIENT_ENCRYPTION          0x0f
+#define ATT_ERROR_UNSUPPORTED_GROUP_TYPE           0x10
+#define ATT_ERROR_INSUFFICIENT_RESOURCES           0x11
 
 // MARK: Attribute Property Flags
 #define ATT_PROPERTY_BROADCAST           0x01
@@ -103,6 +114,11 @@ extern "C" {
 #define ATT_PROPERTY_DYNAMIC             0x100
 // 128 bit UUID used
 #define ATT_PROPERTY_UUID128             0x200
+// Authentication required
+#define ATT_PROPERTY_AUTHENTICATION_REQUIRED 0x400
+// Authorization from user required
+#define ATT_PROPERTY_AUTHORIZATION_REQUIRED  0x800
+// Encryption key size stored in upper 4 bits, 0 == no encryption, encryption key size - 1 otherwise
 
 // MARK: GATT UUIDs
 #define GATT_PRIMARY_SERVICE_UUID      0x2800
@@ -110,8 +126,8 @@ extern "C" {
 #define GATT_INCLUDE_SERVICE_UUID      0x2802
 #define GATT_CHARACTERISTICS_UUID      0x2803
 
-#define GAP_SERVICE_UUID          0x1800
-#define GAP_DEVICE_NAME_UUID      0x2a00
+#define GAP_SERVICE_UUID               0x1800
+#define GAP_DEVICE_NAME_UUID           0x2a00
 
 #define ATT_TRANSACTION_MODE_NONE      0x0
 #define ATT_TRANSACTION_MODE_ACTIVE    0x1
diff --git a/ble/compile-gatt.py b/ble/compile-gatt.py
index 73b067bae..90937f910 100755
--- a/ble/compile-gatt.py
+++ b/ble/compile-gatt.py
@@ -41,18 +41,31 @@ assigned_uuids = {
 }
 
 property_flags = {
-    'BROADCAST' :                  0x01,
-    'READ' :                       0x02,
-    'WRITE_WITHOUT_RESPONSE' :     0x04,
-    'WRITE' :                      0x08,
-    'NOTIFY':                      0x10,
-    'INDICATE' :                   0x20,
-    'AUTHENTICATED_SIGNED_WRITE' : 0x40,
-    'EXTENDED_PROPERTIES' :        0x80,
+    'BROADCAST' :                   0x01,
+    'READ' :                        0x02,
+    'WRITE_WITHOUT_RESPONSE' :      0x04,
+    'WRITE' :                       0x08,
+    'NOTIFY':                       0x10,
+    'INDICATE' :                    0x20,
+    'AUTHENTICATED_SIGNED_WRITE' :  0x40,
+    'EXTENDED_PROPERTIES' :         0x80,
     # custom BTstack extension
-    'DYNAMIC':                    0x100,
-    'LONG_UUID':                  0x200,
-    'CLIENT_CONFIGURATION':       0x400,
+    'DYNAMIC':                     0x100,
+    'LONG_UUID':                   0x200,
+    'AUTHENTICATION_REQUIRED':     0x400,
+    'AUTHORIZATION_REQUIRED':      0x800,
+    'ENCRYPTION_KEY_SIZE_7':      0x6000,
+    'ENCRYPTION_KEY_SIZE_8':      0x7000,
+    'ENCRYPTION_KEY_SIZE_9':      0x8000,
+    'ENCRYPTION_KEY_SIZE_10':     0x9000,
+    'ENCRYPTION_KEY_SIZE_11':     0xa000,
+    'ENCRYPTION_KEY_SIZE_12':     0xb000,
+    'ENCRYPTION_KEY_SIZE_13':     0xc000,
+    'ENCRYPTION_KEY_SIZE_14':     0xd000,
+    'ENCRYPTION_KEY_SIZE_15':     0xe000,
+    'ENCRYPTION_KEY_SIZE_16':     0xf000,
+    # only used by gatt compiler
+    'CLIENT_CONFIGURATION':      0x10000,
 }
 
 services = dict()
@@ -107,7 +120,7 @@ def write_8(fout, value):
     fout.write( "0x%02x, " % (value & 0xff))
 
 def write_16(fout, value):
-    fout.write('0x%02x, 0x%02x, ' % (value & 0xff, value >> 8))
+    fout.write('0x%02x, 0x%02x, ' % (value & 0xff, (value >> 8) & 0xff))
 
 def write_uuid(uuid):
     for byte in uuid: