Demystifying the Role of zk-SNARKs in Zcash

TL;DR

This paper explains how zk-SNARKs enable Zcash to provide privacy-preserving digital currency transactions by constructing and analyzing the underlying zero-knowledge proof system.

Contribution

It provides a detailed construction of a zk-SNARK proof and clarifies its crucial role in Zcash's privacy and security features.

Findings

zk-SNARKs enable succinct, non-interactive proofs for privacy

The paper demonstrates the construction of a concrete zk-SNARK

zk-SNARKs are fundamental to Zcash's privacy guarantees

Abstract

Zero-knowledge proofs have always provided a clear solution when it comes to conveying information from a prover to a verifier or vice versa without revealing essential information about the process. Advancements in zero-knowledge have helped develop proofs which are succinct and provide non-interactive arguments of knowledge along with maintaining the zero-knowledge criteria. zk-SNARKs (Zero knowledge Succinct Non-Interactive Argument of Knowledge) are one such method that outshines itself when it comes to advancement of zero-knowledge proofs. The underlying principle of the Zcash algorithm is such that it delivers a full-fledged ledger-based digital currency with strong privacy guarantees and the root of ensuring privacy lies fully on the construction of a proper zk-SNARK. In this paper we elaborate and construct a concrete zk-SNARK proof from scratch and explain its role in the Zcash algorithm.