Editing Travelling Ballot Based Protocol (section)

==Properties==
This type of protocol is subject to double voting and privacy attacks when several voters are colluding.
* Double voting: A corrupted voter can apply the “yes” unitary operation many times without being detected.
* Privacy attack: An adversary that corrupts voters <math>V_{k-1}</math> and <math>V_{k+1}</math> can learn how voter <math>V_k</math> voted with probability 1.