diff --git a/apps/iot/src/endpoint/endpoint_http.erl b/apps/iot/src/endpoint/endpoint_http.erl
index bf9615c..752b274 100644
--- a/apps/iot/src/endpoint/endpoint_http.erl
+++ b/apps/iot/src/endpoint/endpoint_http.erl
@@ -69,8 +69,15 @@ handle_call(get_stat, _From, State = #state{buffer = Buffer}) ->
     {noreply, NewState :: #state{}} |
     {noreply, NewState :: #state{}, timeout() | hibernate} |
     {stop, Reason :: term(), NewState :: #state{}}).
-handle_cast({forward, Metric}, State = #state{buffer = Buffer}) ->
-    NBuffer = endpoint_buffer:append(Metric, Buffer),
+handle_cast({forward, Metric}, State = #state{buffer = Buffer, endpoint = #endpoint{config = #http_endpoint{token = Token}}}) ->
+    Tuple = case is_binary(Token) andalso Token /= <<>> of
+        true ->
+            Sign = iot_util:sha256(erlang:iolist_to_binary([Token, Metric, Token])),
+            {Metric, Sign};
+        false ->
+            {Metric, <<>>}
+    end,
+    NBuffer = endpoint_buffer:append(Tuple, Buffer),
     {noreply, State#state{buffer = NBuffer}};
 
 handle_cast(cleanup, State = #state{buffer = Buffer}) ->
@@ -83,10 +90,14 @@ handle_cast(cleanup, State = #state{buffer = Buffer}) ->
     {noreply, NewState :: #state{}} |
     {noreply, NewState :: #state{}, timeout() | hibernate} |
     {stop, Reason :: term(), NewState :: #state{}}).
-handle_info({next_data, Id, Metric}, State = #state{buffer = Buffer, endpoint = #endpoint{config = #http_endpoint{url = Url}}}) ->
-    Headers = [
-        {<<"Content-Type">>, <<"application/json">>}
-    ],
+handle_info({next_data, Id, {Metric, Sign}}, State = #state{buffer = Buffer, endpoint = #endpoint{config = #http_endpoint{url = Url}}}) ->
+    BaseHeaders = [{<<"Content-Type">>, <<"application/json">>}],
+    ExtraHeaders = if
+                       Sign =:= <<>> -> [];
+                       true -> [{<<"X-Signature">>, Sign}]
+                   end,
+    Headers = BaseHeaders ++ ExtraHeaders,
+
     case hackney:request(post, Url, Headers, Metric) of
         {ok, 200, _, ClientRef} ->
             {ok, RespBody} = hackney:body(ClientRef),
diff --git a/apps/iot/src/iot_util.erl b/apps/iot/src/iot_util.erl
index 9dbde0f..2c97506 100644
--- a/apps/iot/src/iot_util.erl
+++ b/apps/iot/src/iot_util.erl
@@ -113,13 +113,13 @@ assert_call(true, Fun) ->
 assert_call(false, _) ->
     ok.
 
--spec sha256(Str :: string() | binary()) -> string().
+-spec sha256(Str :: string() | binary()) -> binary().
 sha256(Str) when is_list(Str) ->
     sha256(unicode:characters_to_binary(Str));
 sha256(Bin) when is_binary(Bin) ->
     HashBin = crypto:hash(sha256, Bin),
     HexStr = lists:flatten([io_lib:format("~2.16.0B", [B]) || B <- binary:bin_to_list(HashBin)]),
-    string:lowercase(HexStr).
+    list_to_binary(string:lowercase(HexStr)).
 
 -spec md5(Str :: binary()) -> binary().
 md5(Str) when is_binary(Str) ->