Watermarking in e-voting for large scale election

Coercion resistance is the most effective property to fight coercive attacks in Internet elections. This notion was introduced by Juels, Catalano, and Jakobsson (JCJ) at WPES 2005 together with a voting protocol that satisfies such a stringent security requirement. Unfortunately, their scheme has a quadratic complexity (the overhead for tallying authorities is quadratic in the number of votes) and would therefore not be suitable for large scale elections. Then the factor of complexity is very important to practice a voting system on large scale elections. Another drawback of this scheme, is that the mixnet deals Ballots which contain a fake credential. Adding the electronic watermarking on the Ballots could reduce the number of operations in the computing phase. The similarity between valid and fake watermarked ballots and the removal of fake watermarked ones, can reduce the number of Ballots in Input of mixnet. We can use the algorithm proposed by Walton in JCJ scheme to ensure integrity of Ballot and specifically the property of coercion resistance. The scheme of JCJ could be practical if we use watermarking and reduce complexity of computing.