I’ve been trying to sort out some kind of foursquare solver and have ended up deciding to use Wilhelm Plotz’s Cipher Clerk program.

Bion’s solver has some bug that I just can’t work around. 

Cipher clerk also allows for other ciphers to be analyzed and deciphered.  If you’re in the same situation I was, you’ll need to head over to Sun to grab a javascript plugin for Internet Explorer.  On a wireless connection on a laptop, it only took a few minutes and the applet was running fine.

I’m working through an initial run-through of the playfair/bifid/foursquare deciphering with a handful of keywords on my “experiment one” and I’ll post links to results when they’re complete.  This is just the K4 text as-is without the seven “kryptos” letters, no transpositioning.

For those curious, I’m not seeing anything so far but I think we’d all expect that for this first go-through.  If it was just a digraphic cipher it would have been solved by now.  Hopefully some of the upcoming efforts will yield something tangible.