diff --git a/samples/browseable/MediaBrowserService/src/com.example.android.mediabrowserservice/MusicService.java b/samples/browseable/MediaBrowserService/src/com.example.android.mediabrowserservice/MusicService.java
index 8e6e3f273..9f0248b37 100644
--- a/samples/browseable/MediaBrowserService/src/com.example.android.mediabrowserservice/MusicService.java
+++ b/samples/browseable/MediaBrowserService/src/com.example.android.mediabrowserservice/MusicService.java
@@ -39,6 +39,7 @@ import android.os.PowerManager;
 import android.os.SystemClock;
 import android.service.media.MediaBrowserService;
 
+import com.example.android.mediabrowserservice.PackageValidator;
 import com.example.android.mediabrowserservice.model.MusicProvider;
 import com.example.android.mediabrowserservice.utils.LogHelper;
 import com.example.android.mediabrowserservice.utils.MediaIDHelper;
@@ -258,12 +259,11 @@ public class MusicService extends MediaBrowserService implements OnPreparedListe
                 "; clientUid=" + clientUid + " ; rootHints=", rootHints);
         // To ensure you are not allowing any arbitrary app to browse your app's contents, you
         // need to check the origin:
-        if (!ANDROID_AUTO_PACKAGE_NAME.equals(clientPackageName) &&
-                !ANDROID_AUTO_SIMULATOR_PACKAGE_NAME.equals(clientPackageName) &&
-                !getApplication().getPackageName().equals(clientPackageName)) {
+        if (!PackageValidator.isCallerAllowed(this, clientPackageName, clientUid)) {
             // If the request comes from an untrusted package, return null. No further calls will
             // be made to other media browsing methods.
-            LogHelper.w(TAG, "OnGetRoot: IGNORING request from untrusted package " + clientPackageName);
+            LogHelper.w(TAG, "OnGetRoot: IGNORING request from untrusted package "
+                    + clientPackageName);
             return null;
         }
         if (ANDROID_AUTO_PACKAGE_NAME.equals(clientPackageName)) {
diff --git a/samples/browseable/MediaBrowserService/src/com.example.android.mediabrowserservice/PackageValidator.java b/samples/browseable/MediaBrowserService/src/com.example.android.mediabrowserservice/PackageValidator.java
new file mode 100644
index 000000000..d93da9a7a
--- /dev/null
+++ b/samples/browseable/MediaBrowserService/src/com.example.android.mediabrowserservice/PackageValidator.java
@@ -0,0 +1,193 @@
+// Copyright 2014 Google Inc. All Rights Reserved.
+package com.example.android.mediabrowserservice;
+
+import java.io.UnsupportedEncodingException;
+import java.util.Arrays;
+
+import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.os.Process;
+import android.util.Base64;
+import android.util.Log;
+
+/**
+ * Validates that the calling package is authorized to use this {@link MediaBrowserService}.
+ */
+public class PackageValidator {
+    public static final String TAG = "PackageValidator";
+
+    // Replace with your package whitelist
+    static final byte[][] VALID_PUBLIC_SIGNATURES = new byte[][]{
+        // Release Key gearhead-release.x509.pem
+        extractKey(
+        "\060\202\003\275\060\202\002\245\240\003\002\001\002\002\011\000\307\217\236\113" +
+        "\223\101\060\006\060\015\006\011\052\206\110\206\367\015\001\001\005\005\000\060" +
+        "\165\061\013\060\011\006\003\125\004\006\023\002\125\123\061\023\060\021\006\003" +
+        "\125\004\010\014\012\103\141\154\151\146\157\162\156\151\141\061\026\060\024\006" +
+        "\003\125\004\007\014\015\115\157\165\156\164\141\151\156\040\126\151\145\167\061" +
+        "\024\060\022\006\003\125\004\012\014\013\107\157\157\147\154\145\040\111\156\143" +
+        "\056\061\020\060\016\006\003\125\004\013\014\007\101\156\144\162\157\151\144\061" +
+        "\021\060\017\006\003\125\004\003\014\010\147\145\141\162\150\145\141\144\060\036" +
+        "\027\015\061\064\060\065\062\067\062\063\060\065\063\064\132\027\015\064\061\061" +
+        "\060\061\062\062\063\060\065\063\064\132\060\165\061\013\060\011\006\003\125\004" +
+        "\006\023\002\125\123\061\023\060\021\006\003\125\004\010\014\012\103\141\154\151" +
+        "\146\157\162\156\151\141\061\026\060\024\006\003\125\004\007\014\015\115\157\165" +
+        "\156\164\141\151\156\040\126\151\145\167\061\024\060\022\006\003\125\004\012\014" +
+        "\013\107\157\157\147\154\145\040\111\156\143\056\061\020\060\016\006\003\125\004" +
+        "\013\014\007\101\156\144\162\157\151\144\061\021\060\017\006\003\125\004\003\014" +
+        "\010\147\145\141\162\150\145\141\144\060\202\001\042\060\015\006\011\052\206\110" +
+        "\206\367\015\001\001\001\005\000\003\202\001\017\000\060\202\001\012\002\202\001" +
+        "\001\000\323\235\027\016\103\110\261\124\114\137\154\023\275\132\145\244\053\270" +
+        "\072\331\362\064\255\257\344\036\317\113\340\340\202\141\366\312\346\142\302\224" +
+        "\356\255\322\203\103\324\175\123\074\107\365\116\045\260\057\246\043\025\344\210" +
+        "\026\012\041\143\125\200\313\142\116\014\144\023\056\334\201\153\335\140\170\015" +
+        "\142\221\156\360\214\131\051\200\362\135\353\076\323\152\137\276\233\272\334\302" +
+        "\001\017\363\347\275\121\142\246\215\150\122\266\337\172\330\376\232\272\004\246" +
+        "\071\300\357\130\024\113\103\244\370\176\227\131\153\046\157\314\105\035\005\114" +
+        "\241\225\204\043\073\024\047\151\341\233\301\034\234\371\000\075\363\131\000\157" +
+        "\276\134\263\321\072\204\120\011\253\060\311\213\035\343\142\156\140\003\367\013" +
+        "\006\156\204\067\024\154\305\246\223\272\301\213\320\125\103\310\046\222\266\360" +
+        "\252\217\170\003\272\222\264\265\051\334\334\202\232\122\222\130\166\231\323\224" +
+        "\254\244\103\360\261\367\055\221\255\050\134\156\133\206\004\372\353\261\014\013" +
+        "\064\076\142\301\115\326\202\121\057\264\052\372\143\020\214\122\154\337\002\003" +
+        "\001\000\001\243\120\060\116\060\035\006\003\125\035\016\004\026\004\024\032\360" +
+        "\137\140\327\256\350\224\211\122\162\131\012\046\201\032\311\327\316\333\060\037" +
+        "\006\003\125\035\043\004\030\060\026\200\024\032\360\137\140\327\256\350\224\211" +
+        "\122\162\131\012\046\201\032\311\327\316\333\060\014\006\003\125\035\023\004\005" +
+        "\060\003\001\001\377\060\015\006\011\052\206\110\206\367\015\001\001\005\005\000" +
+        "\003\202\001\001\000\224\153\003\143\101\017\273\163\101\110\176\144\352\054\077" +
+        "\300\230\175\173\174\114\301\055\173\022\262\206\226\034\226\242\014\111\063\062" +
+        "\343\000\336\240\321\240\217\037\020\170\320\204\002\373\312\200\227\344\113\355" +
+        "\124\061\352\214\155\265\375\046\337\134\224\031\003\334\065\206\355\330\054\101" +
+        "\114\040\053\363\316\150\054\256\155\331\060\042\346\324\063\205\336\231\021\210" +
+        "\241\131\045\026\121\337\327\360\024\021\242\354\133\242\313\075\101\260\100\376" +
+        "\042\061\320\352\103\153\030\200\162\256\302\157\256\323\205\345\331\017\021\256" +
+        "\103\307\346\035\206\313\307\316\051\022\371\267\015\003\201\374\262\014\222\112" +
+        "\120\111\361\002\325\377\250\077\134\301\336\352\317\123\367\122\274\100\377\054" +
+        "\050\016\166\272\161\147\227\142\355\054\022\312\347\276\126\257\323\145\014\267" +
+        "\342\323\362\200\114\303\331\337\041\026\130\177\311\370\126\220\310\263\071\342" +
+        "\027\161\254\225\001\007\115\237\234\351\006\113\232\313\133\044\030\350\320\103" +
+        "\231\023\154\067\003\316\050\016\331\035\253\252\176\207\011\337\145\345\235\026" +
+        "\041"),
+
+        // Debug Key gearhead.x509.pem
+        extractKey(
+        "\060\202\003\275\060\202\002\245\240\003\002\001\002\002\011\000\347\344\006\360" +
+        "\327\303\226\363\060\015\006\011\052\206\110\206\367\015\001\001\005\005\000\060" +
+        "\165\061\013\060\011\006\003\125\004\006\023\002\125\123\061\023\060\021\006\003" +
+        "\125\004\010\014\012\103\141\154\151\146\157\162\156\151\141\061\026\060\024\006" +
+        "\003\125\004\007\014\015\115\157\165\156\164\141\151\156\040\126\151\145\167\061" +
+        "\024\060\022\006\003\125\004\012\014\013\107\157\157\147\154\145\040\111\156\143" +
+        "\056\061\020\060\016\006\003\125\004\013\014\007\101\156\144\162\157\151\144\061" +
+        "\021\060\017\006\003\125\004\003\014\010\147\145\141\162\150\145\141\144\060\036" +
+        "\027\015\061\064\060\065\062\067\062\063\060\062\065\061\132\027\015\064\061\061" +
+        "\060\061\062\062\063\060\062\065\061\132\060\165\061\013\060\011\006\003\125\004" +
+        "\006\023\002\125\123\061\023\060\021\006\003\125\004\010\014\012\103\141\154\151" +
+        "\146\157\162\156\151\141\061\026\060\024\006\003\125\004\007\014\015\115\157\165" +
+        "\156\164\141\151\156\040\126\151\145\167\061\024\060\022\006\003\125\004\012\014" +
+        "\013\107\157\157\147\154\145\040\111\156\143\056\061\020\060\016\006\003\125\004" +
+        "\013\014\007\101\156\144\162\157\151\144\061\021\060\017\006\003\125\004\003\014" +
+        "\010\147\145\141\162\150\145\141\144\060\202\001\042\060\015\006\011\052\206\110" +
+        "\206\367\015\001\001\001\005\000\003\202\001\017\000\060\202\001\012\002\202\001" +
+        "\001\000\242\356\360\300\022\205\313\071\352\245\032\336\264\235\304\126\236\171" +
+        "\375\212\364\343\320\040\347\011\106\276\260\247\214\203\374\016\263\053\123\353" +
+        "\044\174\247\265\016\154\051\260\263\155\236\030\142\064\177\211\323\115\013\242" +
+        "\115\341\163\310\335\130\247\212\072\212\163\050\140\315\274\277\307\276\164\273" +
+        "\321\234\244\333\250\043\366\073\114\060\174\375\331\246\135\246\154\003\353\261" +
+        "\115\231\071\106\330\121\021\257\344\360\060\076\132\201\243\347\260\124\166\316" +
+        "\126\272\272\005\057\034\154\363\353\226\003\306\220\231\261\017\323\243\014\203" +
+        "\056\174\140\061\250\057\206\364\276\071\354\167\312\035\205\067\272\111\177\004" +
+        "\264\334\247\106\166\105\217\154\272\237\364\127\246\323\333\071\216\067\231\133" +
+        "\363\267\106\011\312\241\023\310\047\204\013\053\275\036\176\060\031\250\234\201" +
+        "\031\300\331\311\003\060\072\317\274\034\211\047\255\247\374\371\304\131\044\074" +
+        "\352\073\036\353\266\331\174\063\162\206\007\141\005\226\064\351\353\361\162\304" +
+        "\222\347\002\216\220\225\171\373\032\266\032\225\062\064\310\265\075\165\002\003" +
+        "\001\000\001\243\120\060\116\060\035\006\003\125\035\016\004\026\004\024\365\003" +
+        "\311\347\022\104\014\017\014\015\003\053\217\110\146\333\360\066\005\031\060\037" +
+        "\006\003\125\035\043\004\030\060\026\200\024\365\003\311\347\022\104\014\017\014" +
+        "\015\003\053\217\110\146\333\360\066\005\031\060\014\006\003\125\035\023\004\005" +
+        "\060\003\001\001\377\060\015\006\011\052\206\110\206\367\015\001\001\005\005\000" +
+        "\003\202\001\001\000\015\312\371\207\121\121\360\212\146\067\210\122\261\100\075" +
+        "\112\160\220\127\045\332\324\144\041\316\224\040\105\261\176\236\231\040\072\175" +
+        "\214\171\272\174\155\335\274\126\227\340\242\200\366\070\023\120\134\045\034\146" +
+        "\111\373\245\150\376\372\353\175\036\023\233\035\126\225\344\123\140\322\227\103" +
+        "\250\271\332\365\006\175\143\212\022\371\232\342\214\256\364\135\237\304\216\126" +
+        "\024\036\370\156\322\222\043\144\006\303\360\051\202\026\132\060\111\036\171\250" +
+        "\044\243\063\230\222\337\262\331\007\175\222\062\275\101\006\046\053\064\013\347" +
+        "\160\250\330\101\122\274\162\324\321\316\032\115\101\003\301\201\160\100\367\305" +
+        "\345\371\335\103\077\055\064\045\144\056\027\113\054\232\022\234\046\353\337\164" +
+        "\111\305\027\261\357\153\034\377\200\044\075\237\066\253\100\215\302\044\037\035" +
+        "\071\165\160\027\311\234\310\064\101\317\202\121\371\200\351\136\216\201\017\347" +
+        "\306\267\136\150\277\354\346\250\057\061\151\077\117\327\362\140\240\065\342\062" +
+        "\034\277\352\274\040\166\057\126\304\367\374\231\276\323\234\020\276\012\113\027" +
+        "\320"),
+    };
+
+    /**
+     * Disallow instantiation of this helper class.
+     */
+    private PackageValidator() {}
+
+    /**
+     * Throws when the caller is not authorized to get data from this MediaBrowserService
+     */
+    public static void checkCallerAllowed(Context context, String callingPackage, int callingUid) {
+        if (!isCallerAllowed(context, callingPackage, callingUid)) {
+            throw new SecurityException("signature check failed.");
+        }
+    }
+
+    /**
+     * @return false if the caller is not authorized to get data from this MediaBrowserService
+     */
+    public static boolean isCallerAllowed(Context context, String callingPackage, int callingUid) {
+        // Always allow calls from the framework or development environment.
+        if (Process.SYSTEM_UID == callingUid || !"user".equals(Build.TYPE)) {
+            return true;
+        }
+        PackageInfo packageInfo;
+        final PackageManager packageManager = context.getPackageManager();
+        try {
+            packageInfo = packageManager.getPackageInfo(
+                    callingPackage, PackageManager.GET_SIGNATURES);
+        } catch (PackageManager.NameNotFoundException ignored) {
+            if (Log.isLoggable(TAG, Log.DEBUG)) {
+                Log.d(TAG, "Package manager can't find package " + callingPackage
+                        + ", defaulting to false");
+            }
+            return false;
+        }
+        if (packageInfo == null) {
+            Log.w(TAG, "Package manager can't find package: " + callingPackage);
+            return false;
+        }
+
+        if (packageInfo.signatures.length != 1) {
+            Log.w(TAG, "Package has more than one signature.");
+            return false;
+        }
+        final byte[] signature = packageInfo.signatures[0].toByteArray();
+
+        for (int i = 0; i < VALID_PUBLIC_SIGNATURES.length; i++) {
+            byte[] validSignature = VALID_PUBLIC_SIGNATURES[i];
+            if (Arrays.equals(validSignature, signature)) {
+                return true;
+            }
+        }
+
+        if (Log.isLoggable(TAG, Log.VERBOSE)) {
+            Log.v(TAG, "Signature not valid.  Found: \n" +
+                    Base64.encodeToString(signature, 0));
+        }
+        return false;
+    }
+
+    private static byte[] extractKey(String keyString) {
+        try {
+            return keyString.getBytes("ISO-8859-1");
+        } catch (UnsupportedEncodingException e) {
+            throw new AssertionError(e);
+        }
+    }
+}