Estonia started this kind of voting in 2005 using chipped IDs and card readers, but it took off in 2011 when the public could vote with their cellphones thanks to a special SIM card and PIN codes. It's appealing beyond the convenience of voting on your own terms, we'd add. You're allowed to change your vote between the start of advance voting and the fourth day before the election (you can't use i-voting on election day), and you can verify that election officials received your vote.

It may take a long while before other countries adopt this model, though. Estonia is a tiny country (just 561,131 people voted in the election), and it's not as juicy a target for foreign interference as the US or western Europe. While Estonia has taken steps to secure the voting process, researchers have discovered vulnerabilities in the past. Any use in a major country would likely need an airtight system where hacks would be extremely difficult.