diff --git a/public/static/js/account/account.js b/public/static/js/account/account.js
new file mode 100644
index 0000000..d0bc3f6
--- /dev/null
+++ b/public/static/js/account/account.js
@@ -0,0 +1,69 @@
+var Account = {
+    original: null,
+    countdown: null,
+
+    openGoogleAuthenticate: function () {
+        window.open('/account/googleAuthenticate', 'googleAuthenticate', 'height=600,width=600')
+    },
+
+    authenticatedWithGoogleCallback: function (authenticatedWithGoogleUntil) {
+        var password = document.getElementsByTagName('form')[0].elements.password;
+        var button = document.getElementById('authenticateWithGoogleButton');
+
+        Account.original = {
+            type: password.type,
+            placeholder: password.placeholder,
+            required: password.required,
+            disabled: password.disabled
+        };
+
+        password.type = 'text';
+        password.placeholder = 'Authenticated!'
+        password.value = '';
+        password.required = false;
+        password.disabled = true;
+
+        button.disabled = true;
+
+        Account.countdown = setInterval(function () {
+            var timeLeft = Math.ceil((authenticatedWithGoogleUntil.getTime() - new Date().getTime()) / 1000);
+
+            if (timeLeft > 30) {
+                return;
+            }
+
+            if (timeLeft <= 0) {
+                Account.resetGoogleAuthentication();
+                return;
+            }
+
+            password.placeholder = 'Authenticated! ' + timeLeft + ' seconds left...';
+        }, 1000);
+    },
+
+    resetGoogleAuthentication: function () {
+        if (Account.countdown !== null) {
+            clearInterval(Account.countdown);
+        }
+
+        var password = document.getElementsByTagName('form')[0].elements.password;
+        var button = document.getElementById('authenticateWithGoogleButton');
+
+        password.type = Account.original.type;
+        password.placeholder = Account.original.placeholder
+        password.required = Account.original.required;
+        password.disabled = Account.original.disabled;
+
+        button.disabled = false;
+    }
+};
+
+(function () {
+    document.getElementById('authenticateWithGoogleButton').onclick = function () {
+        Account.openGoogleAuthenticate();
+    };
+
+    document.getElementsByTagName('form')[0].onreset = function () {
+        Account.resetGoogleAuthentication();
+    };
+})();
diff --git a/public/static/js/account/google_authenticate.js b/public/static/js/account/google_authenticate.js
new file mode 100644
index 0000000..aff35b2
--- /dev/null
+++ b/public/static/js/account/google_authenticate.js
@@ -0,0 +1,10 @@
+(function () {
+    if (success) {
+        window.opener.Account.authenticatedWithGoogleCallback(authenticatedWithGoogleUntil);
+        window.close();
+    } else {
+        document.getElementById('closeWindowButton').onclick = function () {
+            window.close();
+        }
+    }
+})();
diff --git a/src/Controller/UserController.php b/src/Controller/UserController.php
index 06d3d35..25d14e9 100644
--- a/src/Controller/UserController.php
+++ b/src/Controller/UserController.php
@@ -1,16 +1,22 @@
 <?php namespace MapGuesser\Controller;
 
+use DateTime;
 use MapGuesser\Database\Query\Select;
+use MapGuesser\Http\Request;
 use MapGuesser\Interfaces\Authorization\ISecured;
 use MapGuesser\Interfaces\Database\IResultSet;
 use MapGuesser\Interfaces\Request\IRequest;
 use MapGuesser\Interfaces\Response\IContent;
+use MapGuesser\Interfaces\Response\IRedirect;
+use MapGuesser\OAuth\GoogleOAuth;
 use MapGuesser\PersistentData\PersistentDataManager;
 use MapGuesser\PersistentData\Model\User;
 use MapGuesser\PersistentData\Model\UserConfirmation;
 use MapGuesser\Repository\UserConfirmationRepository;
 use MapGuesser\Response\HtmlContent;
 use MapGuesser\Response\JsonContent;
+use MapGuesser\Response\Redirect;
+use MapGuesser\Util\JwtParser;
 
 class UserController implements ISecured
 {
@@ -45,6 +51,63 @@ class UserController implements ISecured
         return new HtmlContent('account/account', $data);
     }
 
+    public function getGoogleAuthenticateRedirect(): IRedirect
+    {
+        /**
+         * @var User $user
+         */
+        $user = $this->request->user();
+
+        $state = bin2hex(random_bytes(16));
+
+        $this->request->session()->set('oauth_state', $state);
+
+        $oAuth = new GoogleOAuth(new Request());
+
+        $url = $oAuth->getDialogUrl(
+            $state,
+            $this->request->getBase() . '/' . \Container::$routeCollection->getRoute('account.googleAuthenticate-action')->generateLink(),
+            $user->getEmail()
+        );
+
+        return new Redirect($url, IRedirect::TEMPORARY);
+    }
+
+    public function authenticateWithGoogle(): IContent
+    {
+        /**
+         * @var User $user
+         */
+        $user = $this->request->user();
+
+        if ($this->request->query('state') !== $this->request->session()->get('oauth_state')) {
+            $data = ['success' => false];
+            return new HtmlContent('account/google_authenticate', $data);
+        }
+
+        $oAuth = new GoogleOAuth(new Request());
+        $tokenData = $oAuth->getToken($this->request->query('code'), $this->request->getBase() . '/' . \Container::$routeCollection->getRoute('account.googleAuthenticate-action')->generateLink());
+
+        if (!isset($tokenData['id_token'])) {
+            $data = ['success' => false];
+            return new HtmlContent('account/google_authenticate', $data);
+        }
+
+        $jwtParser = new JwtParser($tokenData['id_token']);
+        $userData = $jwtParser->getPayload();
+
+        if ($userData['sub'] !== $user->getGoogleSub()) {
+            $data = ['success' => false, 'errorText' => 'This Google account is not linked to your account.'];
+            return new HtmlContent('account/google_authenticate', $data);
+        }
+
+        $authenticatedWithGoogleUntil = new DateTime('+45 seconds');
+        $this->request->session()->set('authenticated_with_google_until', $authenticatedWithGoogleUntil);
+
+        $data = ['success' => true, 'authenticatedWithGoogleUntil' => $authenticatedWithGoogleUntil];
+        return new HtmlContent('account/google_authenticate', $data);
+    }
+
     public function getDeleteAccount(): IContent
     {
         /**
@@ -63,8 +126,13 @@ class UserController implements ISecured
          */
         $user = $this->request->user();
 
-        if (!$user->checkPassword($this->request->post('password'))) {
-            $data = ['error' => ['errorText' => 'The given current password is wrong.']];
+        if (!$this->confirmUserIdentity(
+            $user,
+            $this->request->session()->get('authenticated_with_google_until'),
+            $this->request->post('password'),
+            $error
+        )) {
+            $data = ['error' => ['errorText' => $error]];
             return new JsonContent($data);
         }
 
@@ -84,6 +152,8 @@ class UserController implements ISecured
 
         $this->pdm->saveToDb($user);
 
+        $this->request->session()->delete('authenticated_with_google_until');
+
         $data = ['success' => true];
         return new JsonContent($data);
     }
@@ -95,8 +165,13 @@ class UserController implements ISecured
          */
         $user = $this->request->user();
 
-        if (!$user->checkPassword($this->request->post('password'))) {
-            $data = ['error' => ['errorText' => 'The given current password is wrong.']];
+        if (!$this->confirmUserIdentity(
+            $user,
+            $this->request->session()->get('authenticated_with_google_until'),
+            $this->request->post('password'),
+            $error
+        )) {
+            $data = ['error' => ['errorText' => $error]];
             return new JsonContent($data);
         }
 
@@ -110,7 +185,28 @@ class UserController implements ISecured
 
         \Container::$dbConnection->commit();
 
+        $this->request->session()->delete('authenticated_with_google_until');
+
         $data = ['success' => true];
         return new JsonContent($data);
     }
+
+    private function confirmUserIdentity(User $user, ?DateTime $authenticatedWithGoogleUntil, ?string $password, &$error): bool
+    {
+        if ($authenticatedWithGoogleUntil !== null && $authenticatedWithGoogleUntil > new DateTime()) {
+            return true;
+        }
+
+        if ($password !== null) {
+            if ($user->checkPassword($password)) {
+                return true;
+            }
+
+            $error = 'The given current password is wrong.';
+            return false;
+        }
+
+        $error = 'Could not confirm your identity. Please try again!';
+        return false;
+    }
 }
diff --git a/views/account/account.php b/views/account/account.php
index f6186b6..f1452f6 100644
--- a/views/account/account.php
+++ b/views/account/account.php
@@ -1,10 +1,27 @@
+@js('js/account/account.js')
+
 @extends('templates/layout_normal')
 
 @section('main')
     <h2>Account</h2>
     <div class="box">
         <form id="accountForm" action="/account" method="post" data-observe-inputs="password_new,password_new_confirm">
-            <input class="big fullWidth" type="password" name="password" placeholder="Current password" required minlength="6" autofocus>
+            <?php if ($user['password'] !== null && $user['google_sub'] !== null): ?>
+                <p class="justify small">Please confirm your identity with your password or with Google to modify your account.</p>
+                <div class="inputWithButton">
+                    <input type="password" name="password" placeholder="Current password" required minlength="6" autofocus><!--
+                 --><button id="authenticateWithGoogleButton" class="yellow" type="button">Google</button>
+                </div>
+            <?php elseif ($user['password'] !== null): ?>
+                <p class="justify small">Please confirm your identity with your password to modify your account.</p>
+                <input class="big fullWidth" type="password" name="password" placeholder="Current password" required minlength="6" autofocus>
+            <?php elseif ($user['google_sub'] !== null): ?>
+                <p class="justify small">Please confirm your identity with Google to modify your account.</p>
+                <div class="inputWithButton">
+                    <input type="text" name="password" placeholder="Authenticate with Google..." disabled><!--
+                 --><button id="authenticateWithGoogleButton" class="yellow" type="button">Google</button>
+                </div>
+            <?php endif; ?>
             <hr>
             <?php /* TODO: disabled for the time being, email modification should be implemented */ ?>
             <input class="big fullWidth" type="email" name="email" placeholder="Email address" value="<?= $user['email'] ?>" disabled>
diff --git a/views/account/delete.php b/views/account/delete.php
index 1b190e7..da22d90 100644
--- a/views/account/delete.php
+++ b/views/account/delete.php
@@ -1,14 +1,32 @@
+@js('js/account/account.js')
+
 @extends('templates/layout_normal')
 
 @section('main')
     <h2>Delete account</h2>
     <div class="box">
         <form id="deleteAccountForm" action="/account/delete" method="post" data-redirect-on-success="/">
-            <p class="justify">Are you sure you want to delete your account? This cannot be undone!</p>
-            <input class="big fullWidth marginTop" type="password" name="password" placeholder="Current password" required minlength="6" autofocus>
+            <p class="justify marginBottom">Are you sure you want to delete your account? This cannot be undone!</p>
+            <?php if ($user['password'] !== null && $user['google_sub'] !== null): ?>
+                <p class="justify small">Please confirm your identity with your password or with Google to delete your account.</p>
+                <div class="inputWithButton">
+                    <input type="password" name="password" placeholder="Current password" required minlength="6" autofocus><!--
+                 --><button id="authenticateWithGoogleButton" class="yellow" type="button">Google</button>
+                </div>
+            <?php elseif ($user['password'] !== null): ?>
+                <p class="justify small">Please confirm your identity with your password to delete your account.</p>
+                <input class="big fullWidth" type="password" name="password" placeholder="Current password" required minlength="6" autofocus>
+            <?php elseif ($user['google_sub'] !== null): ?>
+                <p class="justify small">Please confirm your identity with Google to delete your account.</p>
+                <div class="inputWithButton">
+                    <input type="text" name="password" placeholder="Authenticate with Google..." disabled><!--
+                 --><button id="authenticateWithGoogleButton" class="yellow" type="button">Google</button>
+                </div>
+            <?php endif; ?>
             <p id="deleteAccountFormError" class="formError justify marginTop"></p>
             <div class="right marginTop">
-                <button class="red" type="submit" name="submit">Delete account</button>
+                <button class="red marginRight" type="submit" name="submit">Delete account</button><!--
+             --><a class="button gray marginTop" href="/account" title="Back to account">Cancel</a>
             </div>
         </form>
     </div>
diff --git a/views/account/google_authenticate.php b/views/account/google_authenticate.php
new file mode 100644
index 0000000..12f889f
--- /dev/null
+++ b/views/account/google_authenticate.php
@@ -0,0 +1,28 @@
+@js('js/account/google_authenticate.js')
+
+@extends('templates/layout_minimal')
+
+@section('main')
+    <h2>Authenticate with Google</h2>
+    <?php if (!$success): ?>
+    <div class="box">
+        <p class="error justify">
+            <?php if (isset($errorText)): ?>
+                <?= $errorText ?>
+            <?php else: ?>
+                Authentication with Google failed.
+            <?php endif; ?>
+            Please <a id="closeWindowButton" href="javascript:;" title="Close">close this window/tab</a> and try again!
+        </p>
+    </div>
+    <?php endif; ?>
+@endsection
+
+@section('pageScript')
+<script>
+    var success = <?= $success ? 'true' : 'false' ?>;
+    <?php if (isset($authenticatedWithGoogleUntil)): ?>
+        var authenticatedWithGoogleUntil = new Date('<?= $authenticatedWithGoogleUntil->format('c') ?>');
+    <?php endif; ?>
+</script>
+@endsection
diff --git a/web.php b/web.php
index 5eaffae..6df0859 100644
--- a/web.php
+++ b/web.php
@@ -37,6 +37,8 @@ Container::$routeCollection->group('account', function (MapGuesser\Routing\Route
     $routeCollection->post('account-action', '', [MapGuesser\Controller\UserController::class, 'saveAccount']);
     $routeCollection->get('account.delete', 'delete', [MapGuesser\Controller\UserController::class, 'getDeleteAccount']);
     $routeCollection->post('account.delete-action', 'delete', [MapGuesser\Controller\UserController::class, 'deleteAccount']);
+    $routeCollection->get('account.googleAuthenticate', 'googleAuthenticate', [MapGuesser\Controller\UserController::class, 'getGoogleAuthenticateRedirect']);
+    $routeCollection->get('account.googleAuthenticate-action', 'googleAuthenticate/code', [MapGuesser\Controller\UserController::class, 'authenticateWithGoogle']);
 });
 //Container::$routeCollection->get('maps', 'maps', [MapGuesser\Controller\MapsController::class, 'getMaps']);
 Container::$routeCollection->group('game', function (MapGuesser\Routing\RouteCollection $routeCollection) {