User authentication for HTTPs sender channel

Hi,

I am working on HTTP(s) to IDoc scenario through SAP PI. In the HTTP sender channel, I have selected "HTTPS without client authentication". Does that mean that the basic user name and password authentication is not required while posting IDoc thourgh the url provided to the third party?If not,  can the third party make an HTTPS post to PI server without have a PI user id?

Thanks.