Crossword Help Forum
Forum Rules

Orientfan, it should be an L. Sorry, I can't explain the wordplay.

YELLS is the one-time pad that converts PATSY to OFFER.

Heisenberg, yes, 11ac and the following letter are very close to one of the aliases.

Thanks cloverjo and meursault. I guess I would have got there through resolving the one-time pads but your confirmation was appreciated.

I thought this was a fascinating puzzle about a subject new to me - other than four of the names.