Is it possible to get verification and not have coercion?

I was thinking that the verification would show you a list (with per vote random letters)

Jones : D

Vivek : J

McAlan : C

LaRousse : Q

and you'd remember the letter next to your candidate. You could just lie to a coercer, "I voted Q" and actually have voted D, say.

Not sure how you get from there to a confirmed vote though. It seems to require someone at some point to hold a key that can de-anonymise one's vote.

That said de-anonymising votes in UK elections seems pretty easy, ballot papers have codes on; name and address is checked prior to vote.