diff --git a/btle/custom/custom_helper.cpp b/btle/custom/custom_helper.cpp
index f337ff6..db18c61 100644
--- a/btle/custom/custom_helper.cpp
+++ b/btle/custom/custom_helper.cpp
@@ -200,6 +200,7 @@ error_t custom_decode_uuid_base(uint8_t const *const p_uuid_base,
 error_t custom_add_in_characteristic(uint16_t    service_handle,
                                      ble_uuid_t *p_uuid,
                                      uint8_t     properties,
+                                     GattCharacteristic::ble_gatt_char_required_security_t requiredSecurity,
                                      uint8_t    *p_data,
                                      uint16_t    min_length,
                                      uint16_t    max_length,
@@ -244,11 +245,43 @@ error_t custom_add_in_characteristic(uint16_t    service_handle,
     attr_md.vlen = (min_length == max_length) ? 0 : 1;
 
     if (char_props.read || char_props.notify || char_props.indicate) {
-        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);
+        switch (requiredSecurity) {
+            case GattCharacteristic::SECURITY_MODE_ENCRYPTION_OPEN_LINK :
+                BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);
+                break;
+            case GattCharacteristic::SECURITY_MODE_ENCRYPTION_NO_MITM :
+                BLE_GAP_CONN_SEC_MODE_SET_ENC_NO_MITM(&attr_md.read_perm);
+                break;
+            case GattCharacteristic::SECURITY_MODE_ENCRYPTION_WITH_MITM :
+                BLE_GAP_CONN_SEC_MODE_SET_ENC_WITH_MITM(&attr_md.read_perm);
+                break;
+            case GattCharacteristic::SECURITY_MODE_SIGNED_NO_MITM :
+                BLE_GAP_CONN_SEC_MODE_SET_SIGNED_NO_MITM(&attr_md.read_perm);
+                break;
+            case GattCharacteristic::SECURITY_MODE_SIGNED_WITH_MITM :
+                BLE_GAP_CONN_SEC_MODE_SET_SIGNED_WITH_MITM(&attr_md.read_perm);
+                break;
+        };
     }
 
     if (char_props.write || char_props.write_wo_resp) {
-        BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm);
+        switch (requiredSecurity) {
+            case GattCharacteristic::SECURITY_MODE_ENCRYPTION_OPEN_LINK :
+                BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.write_perm);
+                break;
+            case GattCharacteristic::SECURITY_MODE_ENCRYPTION_NO_MITM :
+                BLE_GAP_CONN_SEC_MODE_SET_ENC_NO_MITM(&attr_md.write_perm);
+                break;
+            case GattCharacteristic::SECURITY_MODE_ENCRYPTION_WITH_MITM :
+                BLE_GAP_CONN_SEC_MODE_SET_ENC_WITH_MITM(&attr_md.write_perm);
+                break;
+            case GattCharacteristic::SECURITY_MODE_SIGNED_NO_MITM :
+                BLE_GAP_CONN_SEC_MODE_SET_SIGNED_NO_MITM(&attr_md.write_perm);
+                break;
+            case GattCharacteristic::SECURITY_MODE_SIGNED_WITH_MITM :
+                BLE_GAP_CONN_SEC_MODE_SET_SIGNED_WITH_MITM(&attr_md.write_perm);
+                break;
+        };
     }
 
     ble_gatts_attr_t attr_char_value = {0};
diff --git a/btle/custom/custom_helper.h b/btle/custom/custom_helper.h
index e5c54d5..c04ed4b 100644
--- a/btle/custom/custom_helper.h
+++ b/btle/custom/custom_helper.h
@@ -20,6 +20,7 @@
 #include "common/common.h"
 #include "ble.h"
 #include "UUID.h"
+#include "GattCharacteristic.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -33,6 +34,7 @@ ble_uuid_t custom_convert_to_nordic_uuid(const UUID &uuid);
 error_t custom_add_in_characteristic(uint16_t                  service_handle,
                                      ble_uuid_t               *p_uuid,
                                      uint8_t                   properties,
+                                     GattCharacteristic::ble_gatt_char_required_security_t requiredSecurity,
                                      uint8_t                  *p_data,
                                      uint16_t                  min_length,
                                      uint16_t                  max_length,
diff --git a/nRF51GattServer.cpp b/nRF51GattServer.cpp
index 18ff4b0..464456d 100644
--- a/nRF51GattServer.cpp
+++ b/nRF51GattServer.cpp
@@ -86,6 +86,7 @@ ble_error_t nRF51GattServer::addService(GattService &service)
                  custom_add_in_characteristic(BLE_GATT_HANDLE_INVALID,
                                               &nordicUUID,
                                               p_char->getProperties(),
+                                              p_char->getRequiredSecurity(),
                                               p_char->getValueAttribute().getValuePtr(),
                                               p_char->getValueAttribute().getInitialLength(),
                                               p_char->getValueAttribute().getMaxLength(),