diff --git a/tensorrt_llm/executor/utils.py b/tensorrt_llm/executor/utils.py
index e52ea481fb..9801ee1cd2 100644
--- a/tensorrt_llm/executor/utils.py
+++ b/tensorrt_llm/executor/utils.py
@@ -55,9 +55,9 @@ def create_mpi_comm_session(
         logger_debug(
             f"Using RemoteMpiPoolSessionClient to bind to external MPI processes at {get_spawn_proxy_process_ipc_addr_env()}\n",
             "yellow")
-        get_spawn_proxy_process_ipc_hmac_key_env()
+        hmac_key = get_spawn_proxy_process_ipc_hmac_key_env()
         return RemoteMpiCommSessionClient(
-            addr=get_spawn_proxy_process_ipc_addr_env())
+            addr=get_spawn_proxy_process_ipc_addr_env(), hmac_key=hmac_key)
     else:
         logger_debug(
             f"Using MpiCommSession to bind to external MPI processes\n",
diff --git a/tensorrt_llm/llmapi/mgmn_leader_node.py b/tensorrt_llm/llmapi/mgmn_leader_node.py
index 85f8561ebe..2b1d11b0cc 100644
--- a/tensorrt_llm/llmapi/mgmn_leader_node.py
+++ b/tensorrt_llm/llmapi/mgmn_leader_node.py
@@ -9,7 +9,9 @@ import zmq
 
 from tensorrt_llm._utils import global_mpi_rank, mpi_world_size
 from tensorrt_llm.executor.ipc import ZeroMqQueue
-from tensorrt_llm.executor.utils import get_spawn_proxy_process_ipc_addr_env
+from tensorrt_llm.executor.utils import (
+    get_spawn_proxy_process_ipc_addr_env,
+    get_spawn_proxy_process_ipc_hmac_key_env)
 from tensorrt_llm.llmapi.mpi_session import RemoteMpiCommSessionServer
 from tensorrt_llm.llmapi.utils import logger_debug
 
@@ -23,6 +25,7 @@ def launch_server_main(sub_comm=None):
         comm=sub_comm,
         n_workers=num_ranks,
         addr=get_spawn_proxy_process_ipc_addr_env(),
+        hmac_key=get_spawn_proxy_process_ipc_hmac_key_env(),
         is_comm=True)
     logger_debug(
         f"MPI Comm Server started at {get_spawn_proxy_process_ipc_addr_env()}")
@@ -32,8 +35,9 @@ def launch_server_main(sub_comm=None):
 
 
 def stop_server_main():
-    queue = ZeroMqQueue((get_spawn_proxy_process_ipc_addr_env(), None),
-                        use_hmac_encryption=False,
+    hmac_key = get_spawn_proxy_process_ipc_hmac_key_env()
+    queue = ZeroMqQueue((get_spawn_proxy_process_ipc_addr_env(), hmac_key),
+                        use_hmac_encryption=bool(hmac_key),
                         is_server=False,
                         socket_type=zmq.PAIR)
 
diff --git a/tests/unittest/llmapi/_run_mpi_comm_task.py b/tests/unittest/llmapi/_run_mpi_comm_task.py
index b60b7a1efd..94ca4d3865 100644
--- a/tests/unittest/llmapi/_run_mpi_comm_task.py
+++ b/tests/unittest/llmapi/_run_mpi_comm_task.py
@@ -3,6 +3,7 @@ from typing import Literal
 
 import click
 
+from tensorrt_llm.executor.utils import get_spawn_proxy_process_ipc_hmac_key_env
 from tensorrt_llm.llmapi.mpi_session import RemoteMpiCommSessionClient
 from tensorrt_llm.llmapi.utils import print_colored
 
@@ -15,8 +16,9 @@ def main(task_type: Literal["submit", "submit_sync"]):
     tasks = [0]
     assert os.environ[
         'TLLM_SPAWN_PROXY_PROCESS_IPC_ADDR'] is not None, "TLLM_SPAWN_PROXY_PROCESS_IPC_ADDR is not set"
+    hmac_key = get_spawn_proxy_process_ipc_hmac_key_env()
     client = RemoteMpiCommSessionClient(
-        os.environ['TLLM_SPAWN_PROXY_PROCESS_IPC_ADDR'])
+        os.environ['TLLM_SPAWN_PROXY_PROCESS_IPC_ADDR'], hmac_key=hmac_key)
     for task in tasks:
         if task_type == "submit":
             client.submit(print_colored, f"{task}\n", "green")
diff --git a/tests/unittest/llmapi/_run_multi_mpi_comm_tasks.py b/tests/unittest/llmapi/_run_multi_mpi_comm_tasks.py
index 5b50df94f2..440d07149c 100644
--- a/tests/unittest/llmapi/_run_multi_mpi_comm_tasks.py
+++ b/tests/unittest/llmapi/_run_multi_mpi_comm_tasks.py
@@ -3,7 +3,8 @@ from typing import Literal
 
 import click
 
-from tensorrt_llm.executor.utils import LlmLauncherEnvs
+from tensorrt_llm.executor.utils import (
+    LlmLauncherEnvs, get_spawn_proxy_process_ipc_hmac_key_env)
 from tensorrt_llm.llmapi.mpi_session import RemoteMpiCommSessionClient
 from tensorrt_llm.llmapi.utils import print_colored
 
@@ -13,8 +14,10 @@ def run_task(task_type: Literal["submit", "submit_sync"]):
     assert os.environ[
         LlmLauncherEnvs.
         TLLM_SPAWN_PROXY_PROCESS_IPC_ADDR] is not None, "TLLM_SPAWN_PROXY_PROCESS_IPC_ADDR is not set"
+    hmac_key = get_spawn_proxy_process_ipc_hmac_key_env()
     client = RemoteMpiCommSessionClient(
-        os.environ[LlmLauncherEnvs.TLLM_SPAWN_PROXY_PROCESS_IPC_ADDR])
+        os.environ[LlmLauncherEnvs.TLLM_SPAWN_PROXY_PROCESS_IPC_ADDR],
+        hmac_key=hmac_key)
 
     for task in tasks:
         if task_type == "submit":