I am looking for an opening to strangle my opponent. Any suggestions

If you're looking for something to strange your opponents, it would not be prophylactic.  When something is prophylactic, it refers to fixing some sort of problem, usually a positional disadvantage.

Play like Karpov. He is a good positional squeezer.

 Yeah, all you need to do is play like Karpov.  Shouldn't be too hard.

Haha...play like Karpov...

I have some suggestions:

The Krasenkow variation of the KID

6.a4 in the Najdorf

uhh...yea its late and I can't think of anything else off the top of my head. More later!

I would recommend the Ruy Lopez. One slip and black may find his position completely without play

I was under the impression that prophylactic play was preventing your opponent from having opportunities rather than creating any yourself

No, "prophylactic" is just a technical word for "preventative."  Nimzowitsch, who introduced the term to chess strategy, wrote that "weak points, still more strong points, are deserving of overprotection." 

Offensively this might mean, for example, not only placing a Knight on a weak d5 square, but focusing as many other pieces as possible upon controlling that square.  According to Nimzowitsch, such a focal point of pieces increases their power.

Figuring out an opening plan to "strangle" the opponent is difficult, though, because he also has chances to play actively at every turn.