The team behind Zcash, the untraceable digital currency, are set on providing anonymity to cryptocurrency transactions.
What makes Zcash transactions private and virtually untraceable is its encryption called zkSNARK, which stands for Zero-Knowledge Succinct Non-interactive ARgument of Knowledge. Zcash developer Sean Bowe, states in a blog post that a group of programmers met at Cornell University to implement the use of its cryptographic tool, zkSNARK. Vitalik Buterin, Andrew Miller, Eran Tromer and Bowe came together during the Ethereum/IC3 Bootcamp at Cornell in order to develop the completely anonymous transactions on the Ethereum blockchain.
“The ethos of Zcash is to be very inclusive and welcoming,” Bowe explains in his blog. “What we care about is building privacy-enhancing technology, full stop. Whether that’s done through a sidechain, through an altcoin, whatever.”
Using the zkSNARK verifier within the Ethereum platform is known as “baby ZoE” or Zerocash over Ethereum. The contract allows users to deposit unknown, or secret, units of ETH by placing a commitment to a specific serial number that is logged into a merkle tree maintained by baby ZoE.
Withdrawing without revealing each transaction is its own scenario. In order to keep what is being spent a secret, developers simply use a zkSNARK to prove that an allegiance inside the merkle tree of the contract exists. By revealing the serial number after a withdrawal, the reuse of the number is prohibited and double spending is prevented.
Not only will this provide individuals with more privacy, but developers also hope it can reduce the “verification cost of complicated smart contracts.”
Aside from serving as an advisor to the Zcash project, Miller contributed to a white paper, released May 2016, that speaks of his other project called Hawk. Similar to Zcash, Hawk uses the same protocol in order to create a cloud of concealment for the sending and receiving addresses within Ethereum transactions. Further, the concept (Hawk) is a system of smart contracts that can be used to hide the amount of a transaction and its legal entities.
Miller believes these contracts could prove to be useful since all of its data would remain private. However, the contracts would not be available for use with every transaction, but instead on “a case-by-case basis when additional privacy is needed by users of a public blockchain.”
Miller told CoinDesk: “The goal of Hawk is to provide the programmability and expressiveness of [E]thereum while also providing the privacy-preserving nature of Zcash.”
ZkSNARKs are seen as a novelty in cryptographic privacy. These zero-knowledge proofs could help with the progression of ideas in the digital currency field, since “they allow for a prover and verifier to share a common reference without exchanging data.”