Estonia has implemented Internet voting in national elections since 2005 and the percentage of voters voting via Internet has trended up in each successive election. Estonia has taken several measures to ensure the secrecy of the vote, primarily through allowing multiple votes to be cast over the Internet by a voter (only the last one is counted) and also prioritizing any paper ballot cast by a voter over Internet votes cast.

Estonia became the first country to offer Internet voting to the entire electorate for nationwide, binding elections. Internet voting has now been provided in local (2005, 2009), parliamentary (2007, 2011), presidential (2011) and European (2009) elections. The first three elections were carried out without major criticisms and with a growing percentage of Internet voters. The 2011 parliamentary elections saw a significant increase in the usage of Internet voting (over 24 percent of all votes were cast using the Internet).

Internet voting is only available before Election Day during an early voting period that normally lasts for one week. Voters may cast their Internet ballots multiple times during this period, and only the last Internet ballot cast is considered valid for the official tally. Various paper ballot options are also available. Voters can cast early paper ballots. Estonians living abroad may cast their ballots by post or vote at an embassy. Voting from ships is also offered.

The names of those voting by Internet are removed from the electoral register used on Election day in the polling station. Any paper ballot cast in the early voting period will be counted, canceling any Internet ballot cast by the voter. The strategy of allowing multiple votes and the primacy of the paper ballot is intended to protect the secrecy of the vote by allowing any voter who may have been coerced or intimidated to vote a certain way the opportunity to vote again in secrecy and overwrite their previous, tainted vote.

Internet voters identify themselves with a smart national ID card or a “mobile ID” (a new authentication channel using mobile phones with specific SIM cards that was introduced in 2011). Once authenticated, the voter casts the ballot through a platform that sends the vote to a central database. The vote is digitally signed (inner “envelope”) and inserted in another virtual and signed “envelope” (outer one) that contains the identification of the voter and the session log.