At loss about CS specialization/sub-field Unfortunately, I did not know where to post this sort of question as it is very ambiguous. So I figured the Academia forum was the best place to ask, but feel free to point me to another direction. That said, this question is more about getting inspiration, rather than getting answers.

Here's my story: I'm currently studying computer science at college, and finally being top of my class in a particular course has given me the confidence to strive for greater things than I originally thought possible for myself. I want to pursue a job in research, because I would rather help mankind with technological/innovative progress than financial/social progress... So my dream is to acquire myself a well-earned Ph.D.

But here's the thing: I've studied computer security most of my life (leisure-study), and always imagined that this would be my main field of research because I'm very good at this specific area of expertise.

However, recently i've started to rethink this career path. My realization was that this field, albeit obviously not wasteful, was not going to prove beneficial for mankind in general/long-term. Unless we could use these defensive information technologies against a synthetic alien invasion, who's plan A was to destroy our Internet, hindering communications. But somehow I still think they would succeed.

So I have started to look into other areas of computer science. I kinda always had a dream of working with quantum computers (probably more a physics/engineering field at the moment), but i'm not really one of those extremely hardcore nerd types (God bless you guys.), so I suppose that's out of reach for me.

I'm leaning towards artificial intelligence, because I imagine that the two most prominent areas of research that will cause significiant improvements on our way of life will be either quantum computers, for their theoretical astonomical computational powers, and self-aware "strong AIs" that can help our race with all our physical, philosophical and economical problems (to name a few).

But I would still like to know if you guys think I should try to pursue something different. I'm not all that great at mathematics, but i'm extremely committed to my work once I begin, so I wouldn't mind becoming one of those "hardcore nerd types". I looked abit on http://en.wikipedia.org/wiki/Computer_science , and skimmed the theoretical computer science section, but nothing really sticks.

P.S. Please do not provide an answer such as "just learn what you love to learn", but it's not that simple in this case. I love just about everything that has to do with computers, both theory and applied, and computer science isn't a small genre to pick from.

Thank you most sincerely.
Honestly, you sound like someone who is looking for a Magic Bullet to Save The World, not someone who is really informed about or interested in computer science.  You sound like someone in love with the idea of computer science research, but with no real idea what computer science research is.  Computer security against aliens?  Quantum computing?  Artificial intelligence?  These are all dangerously close to science fiction.  There's tons of good research in all those areas, but nothing — in any of those areas — is close to "saving the world", and everything interesting — in all of those areas — requires a fair bit of mathematical maturity.  Sorry, but if you don't like math, you won't like real AI research, or real security research, or real quantum computing research.

If you want to do research, and really do it well, you have to love your tools.  You have to love the math; you have to love the code; you have to love the nights in the lab; you have to love the balky experimental equipment.  You have to love feeling stupid, because researchers spend 99% of their time feeling stupid; they're at the bleeding edge of what mankind understands about Reality, so of course they don't really know what they're doing.  You have to love to work in the face of almost certain failure.  You have to take the world's ignorance, especially your own personal ignorance, as motivation, not frustration.  You have to get over the idea that you are going to Save to World, because you aren't, but you do the work anyway, because you can't not do the work; it's in your blood; it's who you are.

If that's not you, don't bother.  There are much better ways to make money.  There are much better ways to help people.  There are much better ways to be happy than to do something you don't really love because you think it's Cool and Important.

But if you really can't live without doing it, then you really have no choice—do it, and do it well.  And who knows; you may save the world after all!  (But probably not.)