Homomorphic encryption would allow tallying the ballots without decrypting them. Helios [1], for instance uses an homomorphic scheme. There are alternatives t

Homomorphic encryption would allow tallying the ballots without decrypting them. Helios [1], for instance uses an homomorphic scheme. There are alternatives to it though which preserve voter privacy but allow vote tallying. Shuffling is one of them. Cothority [2] implements an e-voting scheme based on Neff Shuffles 1. https://heliosvoting.org/ https://heliosvoting.org/ 2. https://github.com/dedis/cothority/tree/master/evoting https://github.com/dedis/cothority/tree/master/evoting P.S. I contributed to the latter