diff --git a/test/resources/stubs/ets6_free.json b/test/resources/stubs/ets6_free.json
index ccf1b0f..ed83105 100644
--- a/test/resources/stubs/ets6_free.json
+++ b/test/resources/stubs/ets6_free.json
@@ -8,7 +8,7 @@
     "created_by": "ETS6",
     "schema_version": "22",
     "tool_version": "6.1.5686.0",
-    "xknxproject_version": "3.2.0",
+    "xknxproject_version": "3.3.0",
     "language_code": "de-DE"
   },
   "communication_objects": {},
@@ -53,6 +53,7 @@
       "address": "3",
       "project_uid": 16,
       "dpt": null,
+      "data_secure": false,
       "communication_object_ids": [],
       "description": "",
       "comment": ""
@@ -64,6 +65,7 @@
       "address": "2",
       "project_uid": 14,
       "dpt": null,
+      "data_secure": false,
       "communication_object_ids": [],
       "description": "",
       "comment": ""
@@ -75,6 +77,7 @@
       "address": "1",
       "project_uid": 12,
       "dpt": null,
+      "data_secure": false,
       "communication_object_ids": [],
       "description": "",
       "comment": ""
@@ -86,6 +89,7 @@
       "address": "1025",
       "project_uid": 21,
       "dpt": null,
+      "data_secure": false,
       "communication_object_ids": [],
       "description": "",
       "comment": ""
diff --git a/test/resources/stubs/ets6_two_level.json b/test/resources/stubs/ets6_two_level.json
index 1da22db..51e22a5 100644
--- a/test/resources/stubs/ets6_two_level.json
+++ b/test/resources/stubs/ets6_two_level.json
@@ -8,7 +8,7 @@
     "created_by": "ETS6",
     "schema_version": "22",
     "tool_version": "6.1.5686.0",
-    "xknxproject_version": "3.2.0",
+    "xknxproject_version": "3.3.0",
     "language_code": "de-DE"
   },
   "communication_objects": {},
@@ -59,6 +59,7 @@
       "address": "0/1",
       "project_uid": 6,
       "dpt": null,
+      "data_secure": false,
       "communication_object_ids": [],
       "description": "",
       "comment": ""
@@ -70,6 +71,7 @@
       "address": "1/1",
       "project_uid": 8,
       "dpt": null,
+      "data_secure": false,
       "communication_object_ids": [],
       "description": "",
       "comment": ""
diff --git a/test/resources/stubs/module-definition-test.json b/test/resources/stubs/module-definition-test.json
index 6ad1ea9..fb04d83 100644
--- a/test/resources/stubs/module-definition-test.json
+++ b/test/resources/stubs/module-definition-test.json
@@ -8,7 +8,7 @@
     "created_by": "ETS5",
     "schema_version": "20",
     "tool_version": "5.7.1428.39779",
-    "xknxproject_version": "3.2.0",
+    "xknxproject_version": "3.3.0",
     "language_code": "de-DE"
   },
   "communication_objects": {
@@ -246,6 +246,7 @@
         "main": 9,
         "sub": 1
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.1/MD-2_M-1_MI-1_O-2-1_R-1"
       ],
@@ -262,6 +263,7 @@
         "main": 9,
         "sub": 1
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.1/MD-2_M-1_MI-1_O-2-2_R-3"
       ],
@@ -278,6 +280,7 @@
         "main": 9,
         "sub": 1
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.1/O-334_R-21"
       ],
@@ -294,6 +297,7 @@
         "main": 9,
         "sub": 1
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.1/MD-2_M-2_MI-1_O-2-2_R-3"
       ],
@@ -310,6 +314,7 @@
         "main": 9,
         "sub": 1
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.1/MD-2_M-2_MI-1_O-2-1_R-1"
       ],
@@ -326,6 +331,7 @@
         "main": 9,
         "sub": 1
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.2/MD-2_M-1_MI-1_O-2-2_R-3"
       ],
@@ -342,6 +348,7 @@
         "main": 9,
         "sub": 1
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.1/MD-2_M-1_MI-1_O-2-2_R-3",
         "1.1.1/MD-2_M-2_MI-1_O-2-2_R-3",
diff --git a/test/resources/stubs/test_project-ets4.json b/test/resources/stubs/test_project-ets4.json
index af0bbb1..78b47ea 100644
--- a/test/resources/stubs/test_project-ets4.json
+++ b/test/resources/stubs/test_project-ets4.json
@@ -8,7 +8,7 @@
     "created_by": "ETS4",
     "schema_version": "11",
     "tool_version": "ETS 4.2.0 (Build 3884)",
-    "xknxproject_version": "3.2.0",
+    "xknxproject_version": "3.3.0",
     "language_code": "de-DE"
   },
   "communication_objects": {
@@ -199,6 +199,7 @@
         "main": 1,
         "sub": null
       },
+      "data_secure": false,
       "communication_object_ids": [
         "0.0.1/M-0083_A-0013-11-A9D6_O-0_R-10000",
         "0.0.2/M-0002_A-A061-14-BE27_O-10_R-485"
@@ -216,6 +217,7 @@
         "main": 1,
         "sub": null
       },
+      "data_secure": false,
       "communication_object_ids": [
         "0.0.1/M-0083_A-0013-11-A9D6_O-5_R-10005",
         "0.0.2/M-0002_A-A061-14-BE27_O-71_R-1506"
@@ -233,6 +235,7 @@
         "main": 1,
         "sub": null
       },
+      "data_secure": false,
       "communication_object_ids": [
         "0.0.1/M-0083_A-0013-11-A9D6_O-13_R-4",
         "0.0.2/M-0002_A-A061-14-BE27_O-10_R-485"
diff --git a/test/resources/stubs/testprojekt-ets6-functions.json b/test/resources/stubs/testprojekt-ets6-functions.json
index 2134b9a..f520ed4 100644
--- a/test/resources/stubs/testprojekt-ets6-functions.json
+++ b/test/resources/stubs/testprojekt-ets6-functions.json
@@ -8,7 +8,7 @@
     "created_by": "ETS6",
     "schema_version": "22",
     "tool_version": "6.1.5686.0",
-    "xknxproject_version": "3.2.0",
+    "xknxproject_version": "3.3.0",
     "language_code": "de-DE"
   },
   "communication_objects": {},
@@ -56,6 +56,7 @@
         "main": 1,
         "sub": 1
       },
+      "data_secure": false,
       "communication_object_ids": [],
       "description": "Livingroom LivingroomLight",
       "comment": ""
@@ -70,6 +71,7 @@
         "main": 1,
         "sub": 1
       },
+      "data_secure": false,
       "communication_object_ids": [],
       "description": "Livingroom LivingroomLight",
       "comment": ""
diff --git a/test/resources/stubs/xknx_test_project.json b/test/resources/stubs/xknx_test_project.json
index 94c463d..2deba9d 100644
--- a/test/resources/stubs/xknx_test_project.json
+++ b/test/resources/stubs/xknx_test_project.json
@@ -2,13 +2,13 @@
   "info": {
     "project_id": "P-0242",
     "name": "xknx test project",
-    "last_modified": "2023-05-05T14:02:49.64676Z",
+    "last_modified": "2023-09-29T21:48:57.7711452Z",
     "group_address_style": "ThreeLevel",
     "guid": "7aceb083-274e-4568-806f-b8f9df992873",
     "created_by": "ETS5",
     "schema_version": "20",
     "tool_version": "5.7.1428.39779",
-    "xknxproject_version": "3.2.0",
+    "xknxproject_version": "3.3.0",
     "language_code": null
   },
   "communication_objects": {
@@ -384,7 +384,112 @@
         "transmit": true
       },
       "group_address_links": [
-        "2/1/23"
+        "2/1/23",
+        "7/1/2"
+      ]
+    },
+    "1.1.7/MD-2_M-20_MI-1_O-2-2_R-3": {
+      "name": "RTR1 - 2 - Controller",
+      "number": 2,
+      "text": "RTR 1 (...) - Ausgang",
+      "function_text": "Command value - Heating",
+      "description": "",
+      "device_address": "1.1.7",
+      "dpts": [
+        {
+          "main": 5,
+          "sub": 1
+        }
+      ],
+      "object_size": "1 Byte",
+      "flags": {
+        "read": true,
+        "write": false,
+        "communication": true,
+        "update": true,
+        "read_on_init": false,
+        "transmit": true
+      },
+      "group_address_links": [
+        "7/1/1"
+      ]
+    },
+    "1.1.7/MD-2_M-20_MI-1_O-5-0_R-17": {
+      "name": "RTR1 - 0 - RSM",
+      "number": 0,
+      "text": "RTR 1 (...) - Eingang",
+      "function_text": "Setpoint temperature - Active operating mode",
+      "description": "",
+      "device_address": "1.1.7",
+      "dpts": [
+        {
+          "main": 9,
+          "sub": 1
+        }
+      ],
+      "object_size": "2 Bytes",
+      "flags": {
+        "read": false,
+        "write": true,
+        "communication": true,
+        "update": true,
+        "read_on_init": false,
+        "transmit": false
+      },
+      "group_address_links": [
+        "7/1/0"
+      ]
+    },
+    "1.1.7/MD-2_M-20_MI-1_O-5-10_R-18": {
+      "name": "RTR1 - 10 - RSM",
+      "number": 10,
+      "text": "RTR 1 (...) - Ausgang",
+      "function_text": "Setpoint temperature - Active operating mode - Status",
+      "description": "",
+      "device_address": "1.1.7",
+      "dpts": [
+        {
+          "main": 9,
+          "sub": 1
+        }
+      ],
+      "object_size": "2 Bytes",
+      "flags": {
+        "read": true,
+        "write": false,
+        "communication": true,
+        "update": true,
+        "read_on_init": false,
+        "transmit": true
+      },
+      "group_address_links": [
+        "7/0/0"
+      ]
+    },
+    "1.1.7/MD-2_M-20_MI-1_O-7-1_R-45": {
+      "name": "RTR1 - 1 - Sensor",
+      "number": 1,
+      "text": "RTR 1 (...) - Eingang",
+      "function_text": "Room temperature - Measured value 1",
+      "description": "",
+      "device_address": "1.1.7",
+      "dpts": [
+        {
+          "main": 9,
+          "sub": 1
+        }
+      ],
+      "object_size": "2 Bytes",
+      "flags": {
+        "read": false,
+        "write": true,
+        "communication": true,
+        "update": true,
+        "read_on_init": false,
+        "transmit": true
+      },
+      "group_address_links": [
+        "7/1/2"
       ]
     }
   },
@@ -417,7 +522,8 @@
           "devices": [
             "1.1.0",
             "1.1.5",
-            "1.1.6"
+            "1.1.6",
+            "1.1.7"
           ],
           "medium_type": "Twisted Pair (TP)"
         }
@@ -464,6 +570,20 @@
         "1.1.6/O-9_R-9073",
         "1.1.6/O-18_R-7994"
       ]
+    },
+    "1.1.7": {
+      "name": "Heating actuator 6-gang with controller",
+      "hardware_name": "Heizungsaktor 6fach mit Regler Secure",
+      "description": "",
+      "manufacturer_name": "GIRA Giersiepen",
+      "individual_address": "1.1.7",
+      "project_uid": 60,
+      "communication_object_ids": [
+        "1.1.7/MD-2_M-20_MI-1_O-2-2_R-3",
+        "1.1.7/MD-2_M-20_MI-1_O-5-0_R-17",
+        "1.1.7/MD-2_M-20_MI-1_O-5-10_R-18",
+        "1.1.7/MD-2_M-20_MI-1_O-7-1_R-45"
+      ]
     }
   },
   "group_addresses": {
@@ -477,6 +597,7 @@
         "main": 1,
         "sub": 8
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.5/O-101_R-1578"
       ],
@@ -493,6 +614,7 @@
         "main": 1,
         "sub": null
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.5/O-100_R-1577"
       ],
@@ -509,6 +631,7 @@
         "main": 1,
         "sub": 8
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.5/O-71_R-1506"
       ],
@@ -525,6 +648,7 @@
         "main": 1,
         "sub": 8
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.5/O-70_R-1505"
       ],
@@ -541,6 +665,7 @@
         "main": 1,
         "sub": null
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.5/O-41_R-1434"
       ],
@@ -557,6 +682,7 @@
         "main": 1,
         "sub": null
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.5/O-40_R-1433"
       ],
@@ -573,6 +699,7 @@
         "main": 1,
         "sub": 1
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.5/O-4_R-1417"
       ],
@@ -586,6 +713,7 @@
       "address": "2/1/1",
       "project_uid": 43,
       "dpt": null,
+      "data_secure": false,
       "communication_object_ids": [],
       "description": "no dpt",
       "comment": ""
@@ -600,6 +728,7 @@
         "main": 9,
         "sub": null
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.6/O-0_R-665",
         "1.1.6/O-9_R-9073"
@@ -617,6 +746,7 @@
         "main": 9,
         "sub": null
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.6/O-9_R-9073",
         "1.1.6/O-18_R-7994"
@@ -634,6 +764,7 @@
         "main": 9,
         "sub": 1
       },
+      "data_secure": false,
       "communication_object_ids": [],
       "description": "temperature",
       "comment": ""
@@ -648,6 +779,7 @@
         "main": 9,
         "sub": null
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.6/O-9_R-9073"
       ],
@@ -664,11 +796,81 @@
         "main": 1,
         "sub": null
       },
+      "data_secure": false,
       "communication_object_ids": [
         "1.1.6/O-20_R-8108"
       ],
       "description": "",
       "comment": ""
+    },
+    "7/0/0": {
+      "name": "ds 0",
+      "identifier": "GA-15",
+      "raw_address": 14336,
+      "address": "7/0/0",
+      "project_uid": 58,
+      "dpt": {
+        "main": 9,
+        "sub": 1
+      },
+      "data_secure": false,
+      "communication_object_ids": [
+        "1.1.7/MD-2_M-20_MI-1_O-5-10_R-18"
+      ],
+      "description": "security: off (inherited from middle group)",
+      "comment": ""
+    },
+    "7/1/0": {
+      "name": "ds 1",
+      "identifier": "GA-14",
+      "raw_address": 14592,
+      "address": "7/1/0",
+      "project_uid": 57,
+      "dpt": {
+        "main": 9,
+        "sub": 1
+      },
+      "data_secure": true,
+      "communication_object_ids": [
+        "1.1.7/MD-2_M-20_MI-1_O-5-0_R-17"
+      ],
+      "description": "security: auto",
+      "comment": ""
+    },
+    "7/1/1": {
+      "name": "ds 2",
+      "identifier": "GA-16",
+      "raw_address": 14593,
+      "address": "7/1/1",
+      "project_uid": 59,
+      "dpt": {
+        "main": 5,
+        "sub": 1
+      },
+      "data_secure": true,
+      "communication_object_ids": [
+        "1.1.7/MD-2_M-20_MI-1_O-2-2_R-3"
+      ],
+      "description": "security: on",
+      "comment": ""
+    },
+    "7/1/2": {
+      "name": "ds + non ds",
+      "identifier": "GA-17",
+      "raw_address": 14594,
+      "address": "7/1/2",
+      "project_uid": 64,
+      "dpt": {
+        "main": 9,
+        "sub": 1
+      },
+      "data_secure": false,
+      "communication_object_ids": [
+        "1.1.6/O-18_R-7994",
+        "1.1.7/MD-2_M-20_MI-1_O-7-1_R-45"
+      ],
+      "description": "",
+      "comment": ""
     }
   },
   "group_ranges": {
@@ -729,6 +931,37 @@
           "group_ranges": {}
         }
       }
+    },
+    "7": {
+      "name": "DataSecureTest",
+      "address_start": 14336,
+      "address_end": 16383,
+      "group_addresses": [],
+      "comment": "",
+      "group_ranges": {
+        "7/0": {
+          "name": "Non-DS",
+          "address_start": 14336,
+          "address_end": 14591,
+          "group_addresses": [
+            "7/0/0"
+          ],
+          "comment": "",
+          "group_ranges": {}
+        },
+        "7/1": {
+          "name": "DS-Auto",
+          "address_start": 14592,
+          "address_end": 14847,
+          "group_addresses": [
+            "7/1/0",
+            "7/1/1",
+            "7/1/2"
+          ],
+          "comment": "",
+          "group_ranges": {}
+        }
+      }
     }
   },
   "locations": {
diff --git a/test/resources/xknx_test_project.knxproj b/test/resources/xknx_test_project.knxproj
index 313a002..57cf810 100644
Binary files a/test/resources/xknx_test_project.knxproj and b/test/resources/xknx_test_project.knxproj differ
diff --git a/test/xml/test_parser.py b/test/xml/test_parser.py
index dded9ba..79abf0a 100644
--- a/test/xml/test_parser.py
+++ b/test/xml/test_parser.py
@@ -37,7 +37,7 @@ def test_parse_project_ets5():
         parser = XMLParser(knx_project_contents)
         parser.parse()
 
-    assert len(parser.group_addresses) == 13
+    assert len(parser.group_addresses) == 17
     parsed_gas = {ga.address for ga in parser.group_addresses}
     assert len(parsed_gas) == len(parser.group_addresses)
     assert parsed_gas == {
@@ -54,11 +54,15 @@ def test_parse_project_ets5():
         "2/1/21",
         "2/1/22",
         "2/1/23",
+        "7/0/0",
+        "7/1/0",
+        "7/1/1",
+        "7/1/2",
     }
 
     assert len(parser.areas) == 2
     assert len(parser.areas[1].lines) == 2
-    assert len(parser.areas[1].lines[1].devices) == 3
+    assert len(parser.areas[1].lines[1].devices) == 4
     assert len(parser.areas[1].lines[1].devices[0].additional_addresses) == 4
     assert len(parser.areas[1].lines[1].devices[1].com_object_instance_refs) == 7
 
diff --git a/xknxproject/loader/project_loader.py b/xknxproject/loader/project_loader.py
index 2116cfd..b2a1b41 100644
--- a/xknxproject/loader/project_loader.py
+++ b/xknxproject/loader/project_loader.py
@@ -141,6 +141,7 @@ def load(
             project_uid=int(project_uid) if project_uid else None,
             description=group_address_element.get("Description", ""),
             dpt=get_dpt_type(group_address_element.get("DatapointType")),
+            data_secure_key=group_address_element.get("Key"),
             comment=group_address_element.get("Comment", ""),
             style=group_address_style,
         )
diff --git a/xknxproject/models/knxproject.py b/xknxproject/models/knxproject.py
index 41d5f9b..fadac77 100644
--- a/xknxproject/models/knxproject.py
+++ b/xknxproject/models/knxproject.py
@@ -75,6 +75,7 @@ class GroupAddress(TypedDict):
     address: str
     project_uid: int | None
     dpt: DPTType | None
+    data_secure: bool
     communication_object_ids: list[str]
     description: str
     comment: str
diff --git a/xknxproject/models/models.py b/xknxproject/models/models.py
index 4c5febe..6f029f4 100644
--- a/xknxproject/models/models.py
+++ b/xknxproject/models/models.py
@@ -22,6 +22,7 @@ def __init__(
         project_uid: int | None,
         description: str,
         dpt: DPTType | None,
+        data_secure_key: str | None,
         comment: str,
         style: GroupAddressStyle,
     ):
@@ -32,6 +33,7 @@ def __init__(
         self.project_uid = project_uid
         self.description = description
         self.dpt = dpt
+        self.data_secure_key = data_secure_key  # Key as base64 encoded string or None
         self.comment = comment
         self.style = style
         self.address = XMLGroupAddress.str_address(self.raw_address, self.style)
diff --git a/xknxproject/xml/parser.py b/xknxproject/xml/parser.py
index 500aca7..bee57c7 100644
--- a/xknxproject/xml/parser.py
+++ b/xknxproject/xml/parser.py
@@ -144,6 +144,7 @@ def parse(self, language: str | None = None) -> KNXProject:
                 address=group_address.address,
                 project_uid=group_address.project_uid,
                 dpt=group_address.dpt,
+                data_secure=bool(group_address.data_secure_key),
                 communication_object_ids=_com_object_ids,
                 description=group_address.description,
                 comment=html.unescape(rtf_to_text(group_address.comment)),