zk-SNARKs: theory and application to dispute resolution

Abstract: The use of blockchain technology is constantly growing. However, one aspect that has so far been somewhat ignored is the privacy of users. Precisely for this reason, cryptographic efforts in recent years are focusing on zero-knowledge proofs that are compatible with blockchain. The first part of this seminar will introduce zk-SNARKs, a family of zero-knowledge proofs that are finding multiple applications in the blockchain domain due to their succinctness property. Moreover, the created proofs are also very efficient to verify. In the second part, we will present two protocols available on Ethereum that are based on SNARKs, Semaphore and MACI. The former is used to prove membership in a given group and to send a vote without revealing one’s identity, while the latter allows users to vote on chain ensuring good resistance to collusion attacks. Finally, the last part of the seminar will use these protocols to describe a possible dispute resolution protocol on Ethereum.