diff --git a/app/Helpers/PermissionsHelper.php b/app/Helpers/PermissionsHelper.php
new file mode 100644
index 0000000..8409cd0
--- /dev/null
+++ b/app/Helpers/PermissionsHelper.php
@@ -0,0 +1,102 @@
+<?php
+
+namespace App\Helpers;
+
+use App\Album;
+use App\User;
+use Illuminate\Support\Facades\DB;
+
+class PermissionsHelper
+{
+    public function rebuildCache()
+    {
+        // Get a list of albums
+        $albums = Album::all();
+
+        // Get a list of all configured permissions
+        $albumUserPermissions = DB::table('album_user_permissions')->get();
+        $albumGroupPermissions = DB::table('album_group_permissions')->get();
+        $albumAnonPermissions = DB::table('album_anonymous_permissions')->get();
+
+        // Get a list of all user->group memberships
+        $userGroups = DB::table('user_groups')->get();
+
+        // Build a matrix of new permissions
+        $permissionsCache = [];
+
+        /** @var Album $album */
+        foreach ($albums as $album)
+        {
+            $anonymousPermissions = array_filter($albumAnonPermissions->toArray(), function($item) use ($album)
+            {
+                return ($item->album_id == $album->id);
+            });
+
+            foreach ($anonymousPermissions as $anonymousPermission)
+            {
+                $permissionsCache[] = [
+                    'album_id' => $album->id,
+                    'permission_id' => $anonymousPermission->permission_id,
+                    'created_at' => new \DateTime(),
+                    'updated_at' => new \DateTime()
+                ];
+            }
+
+            $userPermissions = array_filter($albumUserPermissions->toArray(), function($item) use ($album)
+            {
+                return ($item->album_id == $album->id);
+            });
+
+            foreach ($userPermissions as $userPermission)
+            {
+                $permissionsCache[] = [
+                    'user_id' => $userPermission->user_id,
+                    'album_id' => $album->id,
+                    'permission_id' => $userPermission->permission_id,
+                    'created_at' => new \DateTime(),
+                    'updated_at' => new \DateTime()
+                ];
+            }
+
+            $groupPermissions = array_filter($albumGroupPermissions->toArray(), function($item) use ($album)
+            {
+                return ($item->album_id == $album->id);
+            });
+
+            foreach ($groupPermissions as $groupPermission)
+            {
+                // Get a list of users in this group, and add one per user
+                $usersInGroup = array_filter($userGroups->toArray(), function($item) use ($groupPermission)
+                {
+                    return $item->group_id = $groupPermission->group_id;
+                });
+
+                foreach ($usersInGroup as $userGroup)
+                {
+                    $permissionsCache[] = [
+                        'user_id' => $userGroup->user_id,
+                        'album_id' => $album->id,
+                        'permission_id' => $groupPermission->permission_id,
+                        'created_at' => new \DateTime(),
+                        'updated_at' => new \DateTime()
+                    ];
+                }
+            }
+        }
+
+        $this->savePermissionsCache($permissionsCache);
+    }
+
+    private function savePermissionsCache(array $cacheToSave)
+    {
+        DB::transaction(function() use ($cacheToSave)
+        {
+            DB::table('album_permissions_cache')->truncate();
+
+            foreach ($cacheToSave as $cacheItem)
+            {
+                DB::table('album_permissions_cache')->insert($cacheItem);
+            }
+        });
+    }
+}
\ No newline at end of file
diff --git a/app/Http/Controllers/Admin/DefaultController.php b/app/Http/Controllers/Admin/DefaultController.php
index a797918..8be8d16 100644
--- a/app/Http/Controllers/Admin/DefaultController.php
+++ b/app/Http/Controllers/Admin/DefaultController.php
@@ -10,6 +10,7 @@ use App\Group;
 use App\Helpers\ConfigHelper;
 use App\Helpers\DbHelper;
 use App\Helpers\MiscHelper;
+use App\Helpers\PermissionsHelper;
 use App\Http\Controllers\Controller;
 use App\Http\Requests\SaveSettingsRequest;
 use App\Label;
@@ -218,6 +219,9 @@ class DefaultController extends Controller
 
     public function rebuildPermissionsCache()
     {
+        $helper = new PermissionsHelper();
+        $helper->rebuildCache();
+
         return response()->json(true);
     }
 
diff --git a/database/migrations/2018_09_14_091046_create_album_permissions_cache_table.php b/database/migrations/2018_09_14_091046_create_album_permissions_cache_table.php
index ab1c524..91b7ca5 100644
--- a/database/migrations/2018_09_14_091046_create_album_permissions_cache_table.php
+++ b/database/migrations/2018_09_14_091046_create_album_permissions_cache_table.php
@@ -14,9 +14,10 @@ class CreateAlbumPermissionsCacheTable extends Migration
     public function up()
     {
         Schema::create('album_permissions_cache', function (Blueprint $table) {
-            $table->unsignedInteger('user_id');
+            $table->unsignedInteger('user_id')->nullable(true);
             $table->unsignedInteger('album_id');
             $table->unsignedInteger('permission_id');
+            $table->timestamps();
 
             $table->foreign('user_id')
                 ->references('id')->on('users')