MySQL remote connection fails with "unknown authentication method"

Question

I am trying to remotely connect to MySQL server online from my local machine, but I am getting the following error:

Warning: PDO::__construct(): The server requested authentication 
method unknown to the client [mysql_old_password] in 
C:\xampp\htdocs\ticket\terminal\sync.php

SQLSTATE[HY000] [2054] The server requested authentication method 
umknown to the client

My local MySQL server version is 5.5.27, libmysql - mysqlnd 5.0.10 The remote MySQL server version is 5.5.23, the mysqlnd version isn't exposed.

I guess it's an incompatible password hash issue, but I do not know how to resolve it. Below is part of my connection code

$dsn = 'mysql:host=184.173.209.193;dbname=my_db_name';
$options = array(PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8',
); 

try {
    $online_dbh = new PDO($dsn, 'myusername', 'mypassword', $options);
    $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    echo "Congratulations!";
} catch (PDOException $e) {
    echo $e->getMessage();
} 

Answer 1

Assuming you're using PHP 5.3+, you could be experiencing one of the Backward Incompatibility Changes:

The new mysqlnd library necessitates the use of MySQL 4.1's newer 41-byte password format. Continued use of the old 16-byte passwords will cause mysql_connect() and similar functions to emit the error, "mysqlnd cannot connect to MySQL 4.1+ using old authentication."

If so, see https://stackoverflow.com/a/1340538/187954 for information on updating your password.