Thanks for the comments! Especially to you Jibb - you somehow managed to explain the game better in one sentence than I ever managed in dozens!
To answer the few questions - yeah, the game mostly communicates via PHP. It is, at it's heart, a browsergame. This means that you'll be able to play it with basically every internet connection. My own here is limited, and DD is the last game to give trouble! It shouldn't go past a few kilobytes for HOURS OF DELIGHT (more accurately, it's in the same range as refreshing a few text-only pages for a few times). Of course, communication via PHP can be a problem as far as security issues are concerned, though nothing of that sort happened last time. I think flash-games face similar issues.
There are some security measurements in place, and we're adding more this time around*. Of course, perfect security is impossible to achieve. We're simply trying to make it so that if people are acting suspiciously for some time, they'll not be able to access all parts of the game, essentially, we'll ban them from partaking in the multiplayer-aspects of the game, where its team-vs-team. They'll still be able to play the dungeons of other people (unless we ban them completely).
Since there is nothing to gain, and no one will ever SEE if you succeed (apart from us admins), I also guess there is really no incentive to cheat. It's not that there is a high-score table for the game, or anything like that.
* - Yeah, I'm not explicitly stating them. I know security through obscurity is a bad idea.
Perhaps this post will get me points for originality at least.
Check out Dungeon Deities! It's amazing and will make you happy, successful and almost certainly more attractive! It might be true!