You should have the adminstrator detail exactly what the issue is. Opera works with encrypted web pages just fine, it's just that some people don't play nice together.
For example: Wells Fargo online banking will barf with an error message that the only supported browsers are IE6 / FF 1.5 / Safari when I try to log in with my 770. I changed the USER_AGENT (essentially the name of the browser that is sent with all web page requests) to look like FF and was then able to log in (securely over https) and do my banking.
I ask the administrator and he tells me that is opera who can't use encryption so the gultig's trick might work if I know how he does that.
Actualy to connect at the university, when I try to rich a web page I got first a page who ask my login and password.
On my laptop it works but with de 770 not.
IIRC, the 770 by default passes a USER_AGENT string that looks like IE6 except for the word Opera in it. Can't tell what's going on at your campus from the very little information that you have provided. You should ask your admin if linux is even supported too.
Id like to know this myself as my work's website insist I have IE 5 > which is a bunch of bs. I hate browser specific sites. If i can be identify as IE it might work.