Speaker-independent speech recognition?

I've got a very specific speech recognition application in mind, and
I'm looking for a reference that will indicate if it's feasible. I
want to recognize just one magic word, which is a very well-solved
problem with high accuracy if we were talking about a boom mike and a
silent environment. The difficulty is that there may be lots of other
noises in the background, other people saying things, etc.

The application is something like a telematics device where you get
its attention by saying "Computer...", except that the word in
question can be assumed to be a unique word nobody would ever use for
any other purpose. However the specifics of this application are
something along the lines of:

- If the computer doesn't recognize that you want its attention, a
ninja will beat you to death with a frozen muskrat, and
- If the computer hears your dog barking and thinks it was you trying
to get its attention, you'll be charged $1,000 for the CPU time.

Is there an article someone can reference for me that will give some
feel for the best I can expect from today's technology? Ideally, some
information on the upper practical % limit to catching validly spoken
words, and the lower practical limit to the number of false positives
I'll see on other noises.

I see a lot of information about % recognition accuracy on the vendor
websites, but they refer mostly to noise-free environments and of
course to large dictionaries.