Is it ensure, insure, or assure?
the system of voting in which voters mark their choices in privacy on uniform ballots printed and distributed by the government or designate their choices by some other secret means. Victoria and South Australia were the first states to introduce secrecy of the ballot (1856), and for that reason the secret ballot is referred to as the Australian ballot. The system spread to Europe and America to meet the growing public and parliamentary demand for protection of voters. The means for securing secrecy vary considerably.