diff --git a/src/SockChatAuth.php b/src/SockChatAuth.php
index d126410..178dca5 100644
--- a/src/SockChatAuth.php
+++ b/src/SockChatAuth.php
@@ -2,41 +2,36 @@
 final class SockChatAuth {
     public static function attempt(string $endPoint, string $secret, string $cookie): object {
         if(!empty($cookie)) {
-            $decoded = str_pad(base64_decode(str_pad(strtr($cookie, '-_', '+/'), strlen($cookie) % 4, '=', STR_PAD_RIGHT)), 37, "\0");
-            $unpacked = unpack('Cversion/Nuser/H*token', $decoded);
+            $method = 'Misuzu';
+            $signature = sprintf('verify#%s#%s#%s', $method, $cookie, $_SERVER['REMOTE_ADDR']);
+            $signature = hash_hmac('sha256', $signature, $secret);
 
-            if(isset($unpacked['version']) && $unpacked['version'] === 1
-                && isset($unpacked['user']) && $unpacked['user'] > 0) {
-                $loginRequest = [
-                    'user_id' => $unpacked['user'],
-                    'token' => 'SESS:' . $cookie,
-                    'ip' => $_SERVER['REMOTE_ADDR'],
-                ];
-                $loginSignature = hash_hmac('sha256', implode('#', $loginRequest), $secret);
-
-                $login = curl_init($endPoint);
-                curl_setopt_array($login, [
-                    CURLOPT_AUTOREFERER => false,
-                    CURLOPT_FAILONERROR => false,
-                    CURLOPT_FOLLOWLOCATION => true,
-                    CURLOPT_HEADER => false,
-                    CURLOPT_POST => true,
-                    CURLOPT_POSTFIELDS => json_encode($loginRequest),
-                    CURLOPT_RETURNTRANSFER => true,
-                    CURLOPT_TCP_FASTOPEN => true,
-                    CURLOPT_CONNECTTIMEOUT => 2,
-                    CURLOPT_MAXREDIRS => 2,
-                    CURLOPT_PROTOCOLS => CURLPROTO_HTTPS,
-                    CURLOPT_TIMEOUT => 5,
-                    CURLOPT_USERAGENT => 'AJAX Chat',
-                    CURLOPT_HTTPHEADER => [
-                        'Content-Type: application/json',
-                        'X-SharpChat-Signature: ' . $loginSignature,
-                    ],
-                ]);
-                $userInfo = json_decode(curl_exec($login));
-                curl_close($login);
-            }
+            $login = curl_init($endPoint);
+            curl_setopt_array($login, [
+                CURLOPT_AUTOREFERER => false,
+                CURLOPT_FAILONERROR => false,
+                CURLOPT_FOLLOWLOCATION => true,
+                CURLOPT_HEADER => false,
+                CURLOPT_POST => true,
+                CURLOPT_POSTFIELDS => http_build_query([
+                    'method' => $method,
+                    'token' => $cookie,
+                    'ipaddr' => $_SERVER['REMOTE_ADDR'],
+                ], '', '&', PHP_QUERY_RFC3986),
+                CURLOPT_RETURNTRANSFER => true,
+                CURLOPT_TCP_FASTOPEN => true,
+                CURLOPT_CONNECTTIMEOUT => 2,
+                CURLOPT_MAXREDIRS => 2,
+                CURLOPT_PROTOCOLS => CURLPROTO_HTTPS,
+                CURLOPT_TIMEOUT => 5,
+                CURLOPT_USERAGENT => 'AJAX Chat',
+                CURLOPT_HTTPHEADER => [
+                    'Content-Type: application/x-www-form-urlencoded',
+                    'X-SharpChat-Signature: ' . $signature,
+                ],
+            ]);
+            $userInfo = json_decode(curl_exec($login));
+            curl_close($login);
         }
 
         if(empty($userInfo->success)) {