Not really, you just have to be given a number that you can later match, no one has to know that number is you. Could even digitally sign things.
I propose a system where each vote is broadcast to multiple counting organisations, to avoid the counters being biased, and each vote is numbered, but only the voter knows that number so they can check with any counting organisation that it was recorded as they wished.
E-voting makes better forms of voting cheaper, instead of just First Past The Post. Preference voting for example.
If you just give out a number you suddenly open up the system to voter coercion. I can actually prove to you how I voted. Also, as a voter I can't be sure that they system that gives me the number does not save the link between it and me.
For preference voting you don't need e-voting. Using computers to help you count ballots (with an analog check and fallback option) is possible without actually collecting the votes electronically.
Much more of an issue that people don't vote than people sell their votes, which they do indirectly anyway.
Does anywhere use computer printed ballots?, to avoid ambiguously filled out ballots.
Computer creates PNG, you print that, or it's printed at a station, you carry that paper to the vote counting machine, it's optically read, (and read by humans if you wish) without errors because it was just printed by a computer
With online banking there is a paper trail of every action taken. If we want secrecy of the vote that's suddenly a lot harder to do.