Individual verification of Estonian internet voting scheme

Estonia has been using the Estonian Internet Voting scheme for state-wide legally binding general elections since 2005. By means of this, voters can vote not only paper-based voting by using the conventional method but also on the internet with their personal computers. This brought many advantages such as the ease of voting over the internet, the use of electronic devices in the counting processes, and its speed, but it also brought different problem spaces in terms of security. The new system must ensure vote privacy and it must be at least as safe as the conventional election system. In addition, it must not be able to prove the voting cast by other people in any way. From this point of view, the problems brought by the new system are covered with new generation technologies and developing cryptography science. Estonia Internet Voting scheme has been developed over the time with various updates. In the 2011 election period, the individual vote verification component was added to the system as a result of developing an attack against the election system and encountering invalid vote in the central server. The individual vote verification component was added to cover the weakness, but it caused a new weakness regarding vote privacy in the system. There was a solution suggestion regarding the weakness, but unfortunately, a solution that could be used in practice was not offered. In this study, the scheme labeled as IVXV, which was updated later in 2016 and is currently being used, is shown to still have the same weakness and solutions that can be applied in practice is proposed in order to eliminate this weakness.