Are Allen key or Security Key skewers appropriate for bikes with rear facing horizontal dropouts I have a surly karate monkey set up as a single speed. The frame has rear facing horizontal dropouts (track style).  

I don't like quick releases due to potential theft when locking up my bike.

Are standard Allen key skewers or security skewers (like hublox or pitlock) going to hold my rear wheel tight enough to avoid sliding forward in the dropouts?  If not, would zefal locking skewers be appropriate?
It depends on how aggressive you ride. If you are a casual rider and rarely do many jumps or drops then they should work just fine. I am a pretty aggressive rider and have snapped more than my fair share of skewers trying to keep the wheel in place. I have also snapped a number of hollow axles because they are just not strong enough for the riding I do. So I switched to solid axles which are stronger (ultimately cheaper too). I have never had a problem with theft since I lock my both wheels with the frame.

If solid axles are not what you are looking for, I like the pitlock (that doesnt have the hex outer body), they can both be removed by a determined thief with a pipe-wrench, but the inactive side is smaller and harder to grip. Either one will hold the wheel in place about the same though.