In general, any process that allows an individual to verify their vote after the fact will enable coercion over voting. For example, in your proposal, an unscrupulous boss could make a demand before the election: "You must tell me the one-time ID you're voting with. If you choose not to, or if that ID doesn't show up in the registry having cast a vote for <candidate>, you're fired." I think that, no matter what the process is, if I can check how I voted I can also be made to check how I voted while someone watches over my shoulder and threatens consequences.