Presumably you could generate some proof that the vote was correctly cast at the moment you cast it, and that 1 corresponds to A and 0 corresponds to B. But tha

Presumably you could generate some proof that the vote was correctly cast at the moment you cast it, and that 1 corresponds to A and 0 corresponds to B. But that proof would not be accessible after you leave the polling booth (because it'd require some ephemeral value that you could retain or throw away).