Update 11/26/11: You can download all of these symbols in PDF and high-res PNG here.

The one thing Symbol Signs lacks is a good symbol for the Adversary. I’ve been using the diapered baby. Thomas likes the Martini glass. And yet both of these are really hacks. We can do better.

Thus I proposed a contest: $200 to the person who could come up with a new AIGA-consistent symbol to use for the adversary. Honestly, I kind of figured I’d never have to shell out. So it’s with pride and some financial trepidation that I today present not one, but two fantastic entries. The first, really a collection of adversaries, comes from my good friend Sam Small:

I particularly like that he provided me with the adversaries in both sexes. In my teaching I’ve been making a concerted effort to provide equal time to both female adversaries. I find that too many male (and even female!) cryptographers implicitly relate adversarial behavior to the male gender. (Apparently the whole Eve thing is just a figleaf.) But this isn’t fair. Women can be attackers too!

Also, I like the devil baby.

Our second entry comes straight from Thomas Ptacek himself. He only has one proposal, but what he lacks in quantity he makes up for in sinisterness:

And so here we are. I’m not quite sure who the winner is — it’ll take some thinking — but I can tell you that thanks to Sam and Thomas the security community is better off today than we were a few weeks ago.

As soon as I have time (this weekend) I’ll post both of these adversaries in downloadable PDF form. I urge you to use them frequently, and to use them wisely.