diff --git a/core/java/android/view/WindowManager.java b/core/java/android/view/WindowManager.java
index 9c4aefe..091844e 100644
--- a/core/java/android/view/WindowManager.java
+++ b/core/java/android/view/WindowManager.java
@@ -163,7 +163,8 @@
             @ViewDebug.IntToString(from = TYPE_KEYGUARD_DIALOG, to = "TYPE_KEYGUARD_DIALOG"),
             @ViewDebug.IntToString(from = TYPE_SYSTEM_ERROR, to = "TYPE_SYSTEM_ERROR"),
             @ViewDebug.IntToString(from = TYPE_INPUT_METHOD, to = "TYPE_INPUT_METHOD"),
-            @ViewDebug.IntToString(from = TYPE_INPUT_METHOD_DIALOG, to = "TYPE_INPUT_METHOD_DIALOG")
+            @ViewDebug.IntToString(from = TYPE_INPUT_METHOD_DIALOG, to = "TYPE_INPUT_METHOD_DIALOG"),
+            @ViewDebug.IntToString(from = TYPE_SECURE_SYSTEM_OVERLAY, to = "TYPE_SECURE_SYSTEM_OVERLAY")
         })
         public int type;
     
@@ -341,7 +342,19 @@
          * Window type: panel that slides out from the status bar
          */
         public static final int TYPE_STATUS_BAR_PANEL   = FIRST_SYSTEM_WINDOW+14;
-        
+
+        /**
+         * Window type: secure system overlay windows, which need to be displayed
+         * on top of everything else.  These windows must not take input
+         * focus, or they will interfere with the keyguard.
+         *
+         * This is exactly like {@link #TYPE_SYSTEM_OVERLAY} except that only the
+         * system itself is allowed to create these overlays.  Applications cannot
+         * obtain permission to create secure system overlays.
+         * @hide
+         */
+        public static final int TYPE_SECURE_SYSTEM_OVERLAY = FIRST_SYSTEM_WINDOW+15;
+
         /**
          * End of types of system windows.
          */
diff --git a/include/ui/InputDispatcher.h b/include/ui/InputDispatcher.h
index 3599163..4955d47 100644
--- a/include/ui/InputDispatcher.h
+++ b/include/ui/InputDispatcher.h
@@ -183,6 +183,7 @@
         TYPE_INPUT_METHOD_DIALOG= FIRST_SYSTEM_WINDOW+12,
         TYPE_WALLPAPER          = FIRST_SYSTEM_WINDOW+13,
         TYPE_STATUS_BAR_PANEL   = FIRST_SYSTEM_WINDOW+14,
+        TYPE_SECURE_SYSTEM_OVERLAY = FIRST_SYSTEM_WINDOW+15,
         LAST_SYSTEM_WINDOW      = 2999,
     };
 
diff --git a/libs/ui/InputDispatcher.cpp b/libs/ui/InputDispatcher.cpp
index 6ba19d7..41123284 100644
--- a/libs/ui/InputDispatcher.cpp
+++ b/libs/ui/InputDispatcher.cpp
@@ -149,7 +149,8 @@
 
 bool InputWindow::isTrustedOverlay() const {
     return layoutParamsType == TYPE_INPUT_METHOD
-            || layoutParamsType == TYPE_INPUT_METHOD_DIALOG;
+            || layoutParamsType == TYPE_INPUT_METHOD_DIALOG
+            || layoutParamsType == TYPE_SECURE_SYSTEM_OVERLAY;
 }
 
 
@@ -1350,7 +1351,7 @@
         target.flags = 0;
         target.xOffset = 0;
         target.yOffset = 0;
-        target.windowType = InputWindow::TYPE_SYSTEM_OVERLAY;
+        target.windowType = -1;
     }
 }
 
diff --git a/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java b/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java
index 3cf4360..43936a4 100755
--- a/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java
+++ b/policy/src/com/android/internal/policy/impl/PhoneWindowManager.java
@@ -93,6 +93,7 @@
 import static android.view.WindowManager.LayoutParams.TYPE_PHONE;
 import static android.view.WindowManager.LayoutParams.TYPE_PRIORITY_PHONE;
 import static android.view.WindowManager.LayoutParams.TYPE_SEARCH_BAR;
+import static android.view.WindowManager.LayoutParams.TYPE_SECURE_SYSTEM_OVERLAY;
 import static android.view.WindowManager.LayoutParams.TYPE_STATUS_BAR;
 import static android.view.WindowManager.LayoutParams.TYPE_STATUS_BAR_PANEL;
 import static android.view.WindowManager.LayoutParams.TYPE_SYSTEM_DIALOG;
@@ -153,6 +154,7 @@
     static final int KEYGUARD_DIALOG_LAYER = 15;
     // things in here CAN NOT take focus, but are shown on top of everything else.
     static final int SYSTEM_OVERLAY_LAYER = 16;
+    static final int SECURE_SYSTEM_OVERLAY_LAYER = 17;
 
     static final int APPLICATION_MEDIA_SUBLAYER = -2;
     static final int APPLICATION_MEDIA_OVERLAY_SUBLAYER = -1;
@@ -631,7 +633,7 @@
             WindowManager.LayoutParams lp = new WindowManager.LayoutParams(
                     WindowManager.LayoutParams.MATCH_PARENT,
                     WindowManager.LayoutParams.MATCH_PARENT);
-            lp.type = WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY;
+            lp.type = WindowManager.LayoutParams.TYPE_SECURE_SYSTEM_OVERLAY;
             lp.flags = 
                 WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE|
                 WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE|
@@ -727,6 +729,7 @@
     public void adjustWindowParamsLw(WindowManager.LayoutParams attrs) {
         switch (attrs.type) {
             case TYPE_SYSTEM_OVERLAY:
+            case TYPE_SECURE_SYSTEM_OVERLAY:
             case TYPE_TOAST:
                 // These types of windows can't receive input events.
                 attrs.flags |= WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
@@ -804,6 +807,8 @@
             return INPUT_METHOD_DIALOG_LAYER;
         case TYPE_SYSTEM_OVERLAY:
             return SYSTEM_OVERLAY_LAYER;
+        case TYPE_SECURE_SYSTEM_OVERLAY:
+            return SECURE_SYSTEM_OVERLAY_LAYER;
         case TYPE_PRIORITY_PHONE:
             return PRIORITY_PHONE_LAYER;
         case TYPE_TOAST:
diff --git a/services/java/com/android/server/LoadAverageService.java b/services/java/com/android/server/LoadAverageService.java
index 0d86429..b6baadb 100644
--- a/services/java/com/android/server/LoadAverageService.java
+++ b/services/java/com/android/server/LoadAverageService.java
@@ -272,7 +272,7 @@
         WindowManager.LayoutParams params = new WindowManager.LayoutParams(
             WindowManager.LayoutParams.WRAP_CONTENT,
             WindowManager.LayoutParams.WRAP_CONTENT,
-            WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
+            WindowManager.LayoutParams.TYPE_SECURE_SYSTEM_OVERLAY,
             WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE|
             WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE,
             PixelFormat.TRANSLUCENT);
diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 7eb295b..de228d9 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -5888,7 +5888,7 @@
                 View v = LayoutInflater.from(mContext).inflate(
                         com.android.internal.R.layout.safe_mode, null);
                 WindowManager.LayoutParams lp = new WindowManager.LayoutParams();
-                lp.type = WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY;
+                lp.type = WindowManager.LayoutParams.TYPE_SECURE_SYSTEM_OVERLAY;
                 lp.width = WindowManager.LayoutParams.WRAP_CONTENT;
                 lp.height = WindowManager.LayoutParams.WRAP_CONTENT;
                 lp.gravity = Gravity.BOTTOM | Gravity.LEFT;