diff --git a/controller/LoginController.php b/controller/LoginController.php
index a870bcc..12f0c9a 100644
--- a/controller/LoginController.php
+++ b/controller/LoginController.php
@@ -18,17 +18,24 @@ public function __construct() {
         if ($_SERVER['REQUEST_METHOD'] === 'GET') {
             $this->view = new View();
 
-            if (!Session::isUserLoggedIn() && Cookie::isCookiesSet()) {
-                LoginModel::validateCookieLogin(Cookie::get('LoginView::CookieName'), Cookie::get('LoginView::CookiePassword'));
-            }
-
             $data = [
-                'message' => Session::get('feedback'),
-                'username' => Session::get('username'),
+                'message' => '',
+                'username' => '',
             ];
 
-            if (Session::get('isUserLoggedIn')) {
-                $this->view->render('LogoutView', $data);
+            if (!(Session::isUserLoggedIn() && LoginModel::checkIfConcurrentSessionExists())) {
+                if (!Session::isUserLoggedIn() && Cookie::isCookiesSet()) {
+                    LoginModel::validateCookieLogin(Cookie::get('LoginView::CookieName'), Cookie::get('LoginView::CookiePassword'));
+                }
+
+                $data = [
+                    'message' => Session::get('feedback'),
+                    'username' => Session::get('username'),
+                ];
+
+                if (Session::get('isUserLoggedIn')) {
+                    $this->view->render('LogoutView', $data);
+                }
             }
 
             $this->view->render('LoginView', $data);
diff --git a/model/LoginModel.php b/model/LoginModel.php
index db97378..17b794e 100644
--- a/model/LoginModel.php
+++ b/model/LoginModel.php
@@ -51,10 +51,12 @@ public static function login(string $username, string $password, bool $remember)
      * @param string $message The message to be displayed instead of default 'Bye bye!'
      */
     public static function logout(string $message = '') {
-        // Clear stored token and sessionId on logout
+        // Clear stored session data in database on logout
         if (Session::get('user')) {
             UserModel::saveTokenByUserName(Session::get('user')['username'], '');
             UserModel::saveSessionIdByUserName(Session::get('user')['username'], '');
+            UserModel::saveIpAdressByUserName(Session::get('user')['username'], '');
+            UserModel::saveBrowserInfoByUserName(Session::get('user')['username'], '');
         }
 
         Session::destroy();
@@ -82,6 +84,9 @@ private static function validateUserCredentials(string $username, string $passwo
         Session::set('isUserLoggedIn', true);
         Session::setOnce('feedback', 'Welcome');
         UserModel::saveSessionIdByUserName($username, session_id());
+        UserModel::saveIpAdressByUserName($username, $_SERVER['REMOTE_ADDR']);
+        UserModel::saveBrowserInfoByUserName($username, $_SERVER['HTTP_USER_AGENT']);
+
         return true;
     }
 
@@ -116,4 +121,23 @@ public static function validateCookieLogin(string $username, string $token) : bo
         self::logout('Wrong information in cookies');
         return false;
     }
+
+    /**
+     * @return bool
+     */
+    public static function checkIfConcurrentSessionExists() : bool {
+        $newUserIpAddress = $_SERVER['REMOTE_ADDR'];
+        $newUserBrowser = $_SERVER['HTTP_USER_AGENT'];
+        $newUserSessionId = session_id();
+
+        $existingUser = UserModel::getUserByUserName(Session::get('user')['username']);
+
+        if ($newUserSessionId === $existingUser['sessionId'] && ($newUserBrowser !== $existingUser['browser'] || $newUserIpAddress !== $existingUser['ip'])) {
+            session_regenerate_id(false);
+            Session::destroy();
+            return true;
+        }
+
+        return false;
+    }
 }
\ No newline at end of file
diff --git a/model/UserModel.php b/model/UserModel.php
index 26cabec..b448a01 100644
--- a/model/UserModel.php
+++ b/model/UserModel.php
@@ -53,38 +53,58 @@ public static function registerNewUser(string $username, string $password) {
     /**
      * @param string $username
      * @param string $token
-     * @throws Exception
      */
     public static function saveTokenByUserName(string $username, string $token) {
-        if (empty($username)) {
-            throw new \Exception('Username must not be empty');
-        }
+        self::saveDataToDatabase($username, $token, "token");
+    }
 
-        $token = empty($token) ? null : $token;
+    /**
+     * @param string $username
+     * @param string $sessionId
+     */
+    public static function saveSessionIdByUserName(string $username, string $sessionId) {
+        self::saveDataToDatabase($username, $sessionId, "sessionId");
+    }
 
-        $database = DatabaseFactory::getFactory()->getConnection();
+    /**
+     * @param string $username
+     * @param string $ipAddress
+     */
+    public static function saveIpAdressByUserName(string $username, string $ipAddress) {
+        self::saveDataToDatabase($username, $ipAddress, "ip");
+    }
 
-        $sql = 'UPDATE AppUser SET token = :token WHERE username = :user_name;';
-        $query = $database->prepare($sql);
-        $query->execute([':token' => $token, ':user_name' => $username]);
+    /**
+     * @param string $username
+     * @param string $browser
+     */
+    public static function saveBrowserInfoByUserName(string $username, string $browser) {
+        self::saveDataToDatabase($username, $browser, "browser");
     }
 
     /**
      * @param string $username
-     * @param string $sessionId
+     * @param string $data
+     * @param string $columnName
      * @throws Exception
      */
-    public static function saveSessionIdByUserName(string $username, string $sessionId) {
+    private static function saveDataToDatabase(string $username, string $data, string $columnName) {
         if (empty($username)) {
             throw new \Exception('Username must not be empty');
         }
 
-        $sessionId = empty($sessionId) ? null : $sessionId;
+        $validColumnNames = ['sessionId', 'token', 'ip', 'browser'];
 
-        $database = DatabaseFactory::getFactory()->getConnection();
+        if (in_array($columnName, $validColumnNames)) {
+            $data = empty($data) ? null : $data;
 
-        $sql = 'UPDATE AppUser SET sessionId = :session_id WHERE username = :user_name;';
-        $query = $database->prepare($sql);
-        $query->execute([':session_id' => $sessionId, ':user_name' => $username]);
+            $database = DatabaseFactory::getFactory()->getConnection();
+
+            $sql = 'UPDATE AppUser SET ' . $columnName . ' = :data WHERE username = :user_name;';
+            $query = $database->prepare($sql);
+            $query->execute([':data' => $data, ':user_name' => $username]);
+        } else {
+            throw new \Exception('Invalid columnName');
+        }
     }
 }
diff --git a/view/LayoutView.php b/view/LayoutView.php
index 5497bc0..5ceb4f8 100644
--- a/view/LayoutView.php
+++ b/view/LayoutView.php
@@ -9,10 +9,10 @@
 <?php if (Session::get("isUserLoggedIn")) {
     echo '<h2>Logged in</h2>';
 } else {
-    if (Session::get('action') === "login") {
-        echo '<a href="?register">Register a new user</a>';
-    } else if (Session::get('action') === "register") {
+    if (Session::get('action') === "register") {
         echo '<a href="?">Back to login</a>';
+    } else {
+        echo '<a href="?register">Register a new user</a>';
     }
     echo '<h2>Not logged in</h2>';
 } ?>