I liked this one. It's clean and classy. It's generous x-height and tight kerning make it a strong logo. What I really liked here is that the organic letterforms nestled neatly into each other much more cleanly than the more modern fonts.

My favorite, mainly because it's much more personal than many of the others. I jike how the letters in this one don't jump out at you until you look for them, but I could also see making the fingerprint bleed a bit more so the letters stand out more. Alternatly, bolder text could be used, but I think it would depend on the scale at which it's being presented.

I wasn't particularly fond of this one, but I figured it fit their image with an emphasis on structure and rigidity. This is ultimately what they went with.

Another fingerprinty one with super-tight kerning. I liked this one too.

Playing with the flow and symmetry between characters. If the client was more amenable to usinge "ae" alone, I think this would be very strong.

Ultracompact... this version incorporates all the letters in one way or another, they've just been combined into what looks like some sort of kanji.