[Newbies] Are the arguments of a URL encrypted when you make an HTTPS connection?

I had a brilliant idea today! Instead of bothering with authentication, I would use unguessable URLs (and/or arguments) for my application - yes I know it is hardly unique, but it might solve a problem for me.

Anyway, after recovering form the shock of my idea, I suddenly realised it would be completely useless if the URL is transmitted in plain text. Does anyone know when the encryption in an SSL session actually kicks in? And is there anything I can set on WAKom to ensure that the URL is protected?

Cheers Andy