I've been writing stuff on cryptography, see [[Talk:Cryptography#Quasi-outline]]. Lots of it is incomplete, or even missing completely, and could really use contributions. The rest could use contributions, comment, criticism, ...
Mostly, I work bottom-up, trying to do the lower-level stuff first, tie it together later. Howard and various others have done quite a bit of related stuff in a more top-down way, covering [[communications security]] for example. We're meeting in the middle in some places, but there are still large gaps in others. This might be a good time for other writers to pitch in.
The top-level article got renamed [[information security]], although there are are various subarticles dealing with things that are indeed electronic-oriented COMSEC.