It would have been easier tif I hadn't made a typo in my original post.
Venona papers (or "Venona Project")...not Verona.
Hey, I'm barely awake here!
Thanks. I went back and did a new Google search for Venona, and now see what you're talking about.
For others like me who are unfamiliar with the Venona Project, it was a joint project of US and UK intelligence agencies that managed to decrypt Soviet correspondence with agents in the US. It revealed that in the post-WWII period the USSR had at least 349 agents in the US. Here's a link to list of identified names:
http://en.wikipedia.org/wiki/List_of_Americans_in_the_Venona_papers