```xml
<!-- app/config/security.xml -->
<?xml version="1.0" encoding="UTF-8"?>
<srv:container xmlns="http://symfony.com/schema/dic/security"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:srv="http://symfony.com/schema/dic/services"
    xsi:schemaLocation="http://symfony.com/schema/dic/services
        http://symfony.com/schema/dic/services/services-1.0.xsd"
>
    <config>
        <!-- ... -->
        <encoder class="Symfony\Component\Security\Core\User\User"
            algorithm="sha512"
        />
    </config>
</srv:container>
```

By the way: Does anybody know why there is no XML schema definition in the Security Bundle?