I think blockchain technology could greatly increase participation, but not necessarily voter turnout. I think blockchain technology would give people more incentive to participate in elections from their houses than them showing up at a voting booth.

Personally, I think it is not necessary for increasing voter turnout and participation. If the two major parties in the US actually offered decent candidates, then voter participation and turnout would go up. It will also go up if more than the two major parties were allowed to debate on a stage that is broadcasted across the country; it's kind of suppressing the other parties (Libertarian, Green, etc.) and not letting them actually hit big topics and reach big crowds.