diff --git a/service-t/src/com/android/server/NsdService.java b/service-t/src/com/android/server/NsdService.java
index ee5f25b..8cf6db7 100644
--- a/service-t/src/com/android/server/NsdService.java
+++ b/service-t/src/com/android/server/NsdService.java
@@ -16,6 +16,7 @@
 
 package com.android.server;
 
+import static android.Manifest.permission.DEVICE_POWER;
 import static android.Manifest.permission.NETWORK_SETTINGS;
 import static android.Manifest.permission.NETWORK_STACK;
 import static android.net.ConnectivityManager.NETID_UNSET;
@@ -2104,11 +2105,17 @@
             if (!SdkLevel.isAtLeastT()) {
                 throw new SecurityException("API is not available in before API level 33");
             }
-            // REGISTER_NSD_OFFLOAD_ENGINE was only added to the SDK in V, but may
-            // be back ported to older builds: accept it as long as it's signature-protected
-            if (PermissionUtils.checkAnyPermissionOf(context, REGISTER_NSD_OFFLOAD_ENGINE)
-                    && (SdkLevel.isAtLeastV() || PermissionUtils.isSystemSignaturePermission(
-                    context, REGISTER_NSD_OFFLOAD_ENGINE))) {
+
+            // REGISTER_NSD_OFFLOAD_ENGINE was only added to the SDK in V.
+            if (SdkLevel.isAtLeastV() && PermissionUtils.checkAnyPermissionOf(context,
+                    REGISTER_NSD_OFFLOAD_ENGINE)) {
+                return;
+            }
+
+            // REGISTER_NSD_OFFLOAD_ENGINE cannot be backport to U. In U, check the DEVICE_POWER
+            // permission instead.
+            if (!SdkLevel.isAtLeastV() && SdkLevel.isAtLeastU()
+                    && PermissionUtils.checkAnyPermissionOf(context, DEVICE_POWER)) {
                 return;
             }
             if (PermissionUtils.checkAnyPermissionOf(context, NETWORK_STACK,
diff --git a/staticlibs/framework/com/android/net/module/util/PermissionUtils.java b/staticlibs/framework/com/android/net/module/util/PermissionUtils.java
index d5b4c90..8315b8f 100644
--- a/staticlibs/framework/com/android/net/module/util/PermissionUtils.java
+++ b/staticlibs/framework/com/android/net/module/util/PermissionUtils.java
@@ -21,15 +21,12 @@
 import static android.Manifest.permission.NETWORK_STACK;
 import static android.content.pm.PackageInfo.REQUESTED_PERMISSION_GRANTED;
 import static android.content.pm.PackageManager.PERMISSION_GRANTED;
-import static android.content.pm.PermissionInfo.PROTECTION_SIGNATURE;
 import static android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.content.Context;
 import android.content.pm.PackageInfo;
-import android.content.pm.PackageManager;
-import android.content.pm.PermissionInfo;
 import android.os.Binder;
 
 import java.io.PrintWriter;
@@ -57,25 +54,6 @@
     }
 
     /**
-     * Return true if the permission has system signature.
-     */
-    public static boolean isSystemSignaturePermission(@NonNull Context context,
-            @NonNull String permission) {
-        try {
-            PermissionInfo permissionInfo = context.getPackageManager().getPermissionInfo(
-                    permission, 0 /* flags */);
-            if (permissionInfo == null) {
-                return false;
-            }
-            return "android".equals(permissionInfo.packageName)
-                    && permissionInfo.getProtection() == PROTECTION_SIGNATURE;
-        } catch (PackageManager.NameNotFoundException ignored) {
-            // Ignored the NameNotFoundException and return false
-        }
-        return false;
-    }
-
-    /**
      * Return true if the context has one of give permission that is allowed
      * for a particular process and user ID running in the system.
      */
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/PermissionUtilsTest.kt b/staticlibs/tests/unit/src/com/android/net/module/util/PermissionUtilsTest.kt
index 028308b..c5a91a4 100644
--- a/staticlibs/tests/unit/src/com/android/net/module/util/PermissionUtilsTest.kt
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/PermissionUtilsTest.kt
@@ -16,15 +16,12 @@
 
 package com.android.net.module.util
 
-import android.Manifest.permission.INTERNET
-import android.Manifest.permission.NETWORK_SETTINGS
 import android.Manifest.permission.NETWORK_STACK
 import android.content.Context
 import android.content.pm.PackageManager
 import android.content.pm.PackageManager.PERMISSION_DENIED
 import android.content.pm.PackageManager.PERMISSION_GRANTED
 import android.net.NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK
-import android.os.Build
 import androidx.test.filters.SmallTest
 import androidx.test.platform.app.InstrumentationRegistry
 import com.android.net.module.util.PermissionUtils.checkAnyPermissionOf
@@ -144,27 +141,4 @@
             Assert.fail("Exception should have not been thrown with system feature enabled")
         }
     }
-
-    @Test
-    @DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
-    fun testIsSystemSignaturePermission() {
-        assertTrue(
-            PermissionUtils.isSystemSignaturePermission(
-                context,
-                NETWORK_SETTINGS
-            )
-        )
-        assertFalse(
-            PermissionUtils
-                .isSystemSignaturePermission(context, PERMISSION_MAINLINE_NETWORK_STACK)
-        )
-        assertFalse(
-            PermissionUtils
-                .isSystemSignaturePermission(context, "test_permission")
-        )
-        assertFalse(
-            PermissionUtils
-                .isSystemSignaturePermission(context, INTERNET)
-        )
-    }
 }
diff --git a/tests/unit/java/com/android/server/NsdServiceTest.java b/tests/unit/java/com/android/server/NsdServiceTest.java
index ffc8aa1..ad87d28 100644
--- a/tests/unit/java/com/android/server/NsdServiceTest.java
+++ b/tests/unit/java/com/android/server/NsdServiceTest.java
@@ -16,6 +16,7 @@
 
 package com.android.server;
 
+import static android.Manifest.permission.DEVICE_POWER;
 import static android.Manifest.permission.NETWORK_SETTINGS;
 import static android.Manifest.permission.NETWORK_STACK;
 import static android.app.ActivityManager.RunningAppProcessInfo.IMPORTANCE_CACHED;
@@ -24,7 +25,6 @@
 import static android.app.ActivityManager.RunningAppProcessInfo.IMPORTANCE_VISIBLE;
 import static android.content.pm.PackageManager.PERMISSION_DENIED;
 import static android.content.pm.PackageManager.PERMISSION_GRANTED;
-import static android.content.pm.PermissionInfo.PROTECTION_SIGNATURE;
 import static android.net.InetAddresses.parseNumericAddress;
 import static android.net.NetworkCapabilities.TRANSPORT_ETHERNET;
 import static android.net.NetworkCapabilities.TRANSPORT_VPN;
@@ -75,7 +75,6 @@
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.pm.PackageManager;
-import android.content.pm.PermissionInfo;
 import android.net.INetd;
 import android.net.Network;
 import android.net.mdns.aidl.DiscoveryInfo;
@@ -170,6 +169,8 @@
 
     @Rule
     public TestRule compatChangeRule = new PlatformCompatChangeRule();
+    @Rule
+    public TestRule ignoreRule = new DevSdkIgnoreRule();
     @Mock Context mContext;
     @Mock PackageManager mPackageManager;
     @Mock ContentResolver mResolver;
@@ -1697,8 +1698,8 @@
 
     @Test
     @EnableCompatChanges(ENABLE_PLATFORM_MDNS_BACKEND)
-    public void testRegisterOffloadEngine_checkPermission()
-            throws PackageManager.NameNotFoundException {
+    @DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+    public void testRegisterOffloadEngine_checkPermission_V() {
         final NsdManager client = connectClient(mService);
         final OffloadEngine offloadEngine = mock(OffloadEngine.class);
         doReturn(PERMISSION_DENIED).when(mContext).checkCallingOrSelfPermission(NETWORK_STACK);
@@ -1708,17 +1709,41 @@
         doReturn(PERMISSION_GRANTED).when(mContext).checkCallingOrSelfPermission(
                 REGISTER_NSD_OFFLOAD_ENGINE);
 
-        PermissionInfo permissionInfo = new PermissionInfo("");
-        permissionInfo.packageName = "android";
-        permissionInfo.protectionLevel = PROTECTION_SIGNATURE;
-        doReturn(permissionInfo).when(mPackageManager).getPermissionInfo(
-                REGISTER_NSD_OFFLOAD_ENGINE, 0);
-        client.registerOffloadEngine("iface1", OffloadEngine.OFFLOAD_TYPE_REPLY,
-                OffloadEngine.OFFLOAD_CAPABILITY_BYPASS_MULTICAST_LOCK,
-                Runnable::run, offloadEngine);
-        client.unregisterOffloadEngine(offloadEngine);
+        doReturn(PERMISSION_DENIED).when(mContext).checkCallingOrSelfPermission(
+                REGISTER_NSD_OFFLOAD_ENGINE);
+        doReturn(PERMISSION_GRANTED).when(mContext).checkCallingOrSelfPermission(DEVICE_POWER);
+        assertThrows(SecurityException.class,
+                () -> client.registerOffloadEngine("iface1", OffloadEngine.OFFLOAD_TYPE_REPLY,
+                        OffloadEngine.OFFLOAD_CAPABILITY_BYPASS_MULTICAST_LOCK, Runnable::run,
+                        offloadEngine));
+        doReturn(PERMISSION_GRANTED).when(mContext).checkCallingOrSelfPermission(
+                REGISTER_NSD_OFFLOAD_ENGINE);
+        final OffloadEngine offloadEngine2 = mock(OffloadEngine.class);
+        client.registerOffloadEngine("iface2", OffloadEngine.OFFLOAD_TYPE_REPLY,
+                OffloadEngine.OFFLOAD_CAPABILITY_BYPASS_MULTICAST_LOCK, Runnable::run,
+                offloadEngine2);
+        client.unregisterOffloadEngine(offloadEngine2);
+    }
 
-        // TODO: add checks to test the packageName other than android
+    @Test
+    @EnableCompatChanges(ENABLE_PLATFORM_MDNS_BACKEND)
+    @DevSdkIgnoreRule.IgnoreAfter(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
+    @DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.TIRAMISU)
+    public void testRegisterOffloadEngine_checkPermission_U() {
+        final NsdManager client = connectClient(mService);
+        final OffloadEngine offloadEngine = mock(OffloadEngine.class);
+        doReturn(PERMISSION_DENIED).when(mContext).checkCallingOrSelfPermission(NETWORK_STACK);
+        doReturn(PERMISSION_DENIED).when(mContext).checkCallingOrSelfPermission(
+                PERMISSION_MAINLINE_NETWORK_STACK);
+        doReturn(PERMISSION_DENIED).when(mContext).checkCallingOrSelfPermission(NETWORK_SETTINGS);
+        doReturn(PERMISSION_GRANTED).when(mContext).checkCallingOrSelfPermission(
+                REGISTER_NSD_OFFLOAD_ENGINE);
+
+        doReturn(PERMISSION_GRANTED).when(mContext).checkCallingOrSelfPermission(DEVICE_POWER);
+        client.registerOffloadEngine("iface2", OffloadEngine.OFFLOAD_TYPE_REPLY,
+                OffloadEngine.OFFLOAD_CAPABILITY_BYPASS_MULTICAST_LOCK, Runnable::run,
+                offloadEngine);
+        client.unregisterOffloadEngine(offloadEngine);
     }