Block chain provides only two advantages: decentralized authentication and decentralized record keeping.
The expense is increased transaction latency and additional programming overhead. But note, this all resides on a computer, not on a paper ballot.
Why would you need decentralized authentication and record keeping if you are running a sting? Also, exactly HOW is the ballot being entered on to the block chain? The goal of using block chain in voting is to ELIMINATE the paper ballot. Each kiosk would have a private key. When the kiosk puts a vote on the block chain, it becomes tamper-proof.
If you want to print a hash on the ballot, you need to have some ID number to hash, and a printed hash. DHS would have the private key. But then why would you need to incorporate a block chain? This make no sense.
And note, Schaffer says nothing about "block chain".