File: [JWT.php](https://github.com/firebase/php-jwt/blob/master/src/JWT.php) ``` php $key = "secret"; $payload= ["id" => 1, "name" => "foo"]; $jwt = JWT::encode( $payload, $key ); ``` Encoding the payload will genrate this JWT ``` eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpZCI6MSwibmFtZSI6ImZvbyJ9.Q4Kee9E8o0Xfo4ADXvYA8t7dN_X_bU9K5w6tXuiSjlU ``` The error arise when I add two extra digits to the signature ( and only two digits ) ``` php $fake = "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpZCI6MSwibmFtZSI6ImZvbyJ9.Q4Kee9E8o0Xfo4ADXvYA8t7dN_X_bU9K5w6tXuiSjlUxx"; print_r( JWT::decode( $fake, $key, ['HS256'] )); ``` The code above will report a warning ``` php Warning: hash_equals(): Expected known_string to be a string, boolean given in vendor/firebasephp-jwt/src/JWT.php on line 237 ```