Is using SOAP over SSL/TLS the simplest and most secure way to make URL calls between websites in PHP?

Using SOAP over SSL/TLS is a secure way to make URL calls between websites in PHP. It ensures that the data exchanged between the client and server is encrypted and secure. To implement this, you need to configure your SOAP client to use SSL/TLS for communication.

$options = array(
    'ssl' => array(
        'verify_peer' => true,
        'verify_peer_name' => true,
        'allow_self_signed' => false,
        'cafile' => '/path/to/cafile.pem',
    )
);

$client = new SoapClient("https://example.com/service.wsdl", array('stream_context' => stream_context_create($options)));