Securing Squid with Cell Phone Proxying?

I use Squid on my debian box to proxy my US CDMA cell phone's web
browser (Openwave) requests.

I'd like to configure password authentication on squid to add security,
but I don't know what kind of encryption, if any, is actually used
between my phone and when the info gets to my squid box, and back to
the phone.

My phone only has an option for a password for authentication, so I
don't know if a username (possibly my phone number?) is also needed.

For US cell phone users who also use Squid, what do you use for
password protection/authentication for your configuration? I do leave
this question a bit open, as I could opt to change carriers at some
point, and having general knowledge of how password protection is
employed on the various US carriers can be helpful.

Thanks.

Scott