diff --git a/src/gd_gui.erl b/src/gd_gui.erl
index 77b8982..05b664b 100644
--- a/src/gd_gui.erl
+++ b/src/gd_gui.erl
@@ -932,13 +932,13 @@ do_grids_mess_sig2(Request = #{"grids"     := 1,
     Cancel = wxButton:new(Dialog, ?wxID_CANCEL),
     _ = wxBoxSizer:add(ButtSz, Affirm, zxw:flags({wide, 5})),
     _ = wxBoxSizer:add(ButtSz, Cancel, zxw:flags({wide, 5})),
-    _ = wxBoxSizer:add(Sizer, InstTx, zxw:flags({wide, 5})),
-    _ = wxBoxSizer:add(Sizer, AcctSz, zxw:flags({wide, 5})),
-    _ = wxBoxSizer:add(Sizer, URL_Sz, zxw:flags({wide, 5})),
+    _ = wxBoxSizer:add(Sizer, InstTx, zxw:flags({base, 5})),
+    _ = wxBoxSizer:add(Sizer, AcctSz, zxw:flags({base, 5})),
+    _ = wxBoxSizer:add(Sizer, URL_Sz, zxw:flags({base, 5})),
     _ = wxBoxSizer:add(Sizer, MessSz, zxw:flags({wide, 5})),
-    _ = wxBoxSizer:add(Sizer, ButtSz, zxw:flags({base, 5})),
+    _ = wxBoxSizer:add(Sizer, ButtSz, zxw:flags(base)),
     ok = wxDialog:setSizer(Dialog, Sizer),
-    ok = wxDialog:setSize(Dialog, {500, 500}),
+    ok = wxDialog:setSize(Dialog, {600, 300}),
     ok = wxBoxSizer:layout(Sizer),
     ok = wxFrame:center(Dialog),
     ok =
@@ -978,7 +978,7 @@ do_grids_mess_sig2(Request = #{"grids"     := 1,
     _ = wxBoxSizer:add(Sizer, AcctSz, zxw:flags({wide, 5})),
     _ = wxBoxSizer:add(Sizer, URL_Sz, zxw:flags({wide, 5})),
     _ = wxBoxSizer:add(Sizer, MessSz, zxw:flags({wide, 5})),
-    _ = wxBoxSizer:add(Sizer, ButtSz, zxw:flags({base, 5})),
+    _ = wxBoxSizer:add(Sizer, ButtSz, zxw:flags(base)),
     ok = wxDialog:setSizer(Dialog, Sizer),
     ok = wxDialog:setSize(Dialog, {500, 500}),
     ok = wxBoxSizer:layout(Sizer),
diff --git a/src/gd_v_express.erl b/src/gd_v_express.erl
index 732d175..bcd33aa 100644
--- a/src/gd_v_express.erl
+++ b/src/gd_v_express.erl
@@ -355,7 +355,46 @@ challenge(State = #s{recvr = PID, keys = #w{wx = KeyP}}, Challenge) ->
             State;
         KeyID ->
             PubKey = list_to_binary(KeyID),
-            handle_challenge(State, PubKey, Challenge)
+            prompt_challenge(State, PubKey, Challenge)
+    end.
+
+prompt_challenge(State = #s{recvr = PID, frame = Frame, j = J}, PubKey, Challenge) ->
+    Dialog = wxDialog:new(Frame, ?wxID_ANY, J("Message Signature Request")),
+    Sizer = wxBoxSizer:new(?wxVERTICAL),
+    Instruction = J("GajuExpress is requesting an authentication signature."),
+    InstTx = wxStaticText:new(Dialog, ?wxID_ANY, Instruction),
+    AcctSz = wxStaticBoxSizer:new(?wxVERTICAL, Dialog, [{label, J("Signature Account")}]),
+    AcctTx = wxStaticText:new(Dialog, ?wxID_ANY, PubKey),
+    _ = wxStaticBoxSizer:add(AcctSz, AcctTx, zxw:flags({wide, 5})),
+    MessSz = wxStaticBoxSizer:new(?wxVERTICAL, Dialog, [{label, J("Message")}]),
+    MessStyle = ?wxTE_MULTILINE bor ?wxTE_READONLY,
+    MessTx = wxTextCtrl:new(Dialog, ?wxID_ANY, [{value, Challenge}, {style, MessStyle}]),
+    _ = wxStaticBoxSizer:add(MessSz, MessTx, zxw:flags({wide, 5})),
+    ButtSz = wxBoxSizer:new(?wxHORIZONTAL),
+    Affirm = wxButton:new(Dialog, ?wxID_OK),
+    Cancel = wxButton:new(Dialog, ?wxID_CANCEL),
+    _ = wxBoxSizer:add(ButtSz, Affirm, zxw:flags({wide, 5})),
+    _ = wxBoxSizer:add(ButtSz, Cancel, zxw:flags({wide, 5})),
+    _ = wxBoxSizer:add(Sizer, InstTx,  zxw:flags({base, 5})),
+    _ = wxBoxSizer:add(Sizer, AcctSz,  zxw:flags({base, 5})),
+    _ = wxBoxSizer:add(Sizer, MessSz,  zxw:flags({wide, 5})),
+    _ = wxBoxSizer:add(Sizer, ButtSz,  zxw:flags(base)),
+    ok = wxDialog:setSizer(Dialog, Sizer),
+    ok = wxDialog:setSize(Dialog, {600, 300}),
+    ok = wxBoxSizer:layout(Sizer),
+    ok = wxFrame:center(Dialog),
+    Outcome =
+        case wxDialog:showModal(Dialog) of
+            ?wxID_OK     -> ok;
+            ?wxID_CANCEL -> cancel
+        end,
+    ok = wxDialog:destroy(Dialog),
+    case Outcome of
+        ok ->
+            handle_challenge(State, PubKey, Challenge);
+        cancel ->
+            ok = gd_n_recvr:stop(PID),
+            State
     end.
 
 handle_challenge(State = #s{recvr = PID}, PubKey, Challenge) ->