Cryptography of e-voting, Andrej Tolič

Abstract of the diploma thesis: The diploma thesis deals with cryptographic building blocks and schemes that enable us to implement secure e-voting. It is desirable for an e-vote to remain secret, but at the same time we would like the possibility for a third party to verify various levels of correctness of execution. Cryptography provides us the necessary tools to simultaneously realize these two seemingly con icting requi- rements. Public-key cryptosystems, secret sharing schemes, zero-knowledge proofs and mixnets are particularly important among aforementioned tools. These building blocks are presented and studied in the context of e-voting. In the thesis we also describe two schemes for cryptographic e-voting. The rst one is a paper-based scheme, and the second is an open source system for internet voting, Helios.

Keywords: e-voting, cryptography, mixnets, zero-knowledge proofs, secret sharing