Ethereum's Byzantium Testnet Just Verified A Private Transaction

Part of a zcash transaction was verified on an ethereum testnet amidst testing for the upcoming Byzantium upgrade.

AccessTimeIconSep 19, 2017 at 6:01 p.m. UTC
Updated Sep 13, 2021 at 6:56 a.m. UTC

The effort to bring the privacy features of zcash to ethereum took a step forward today during testing for the upcoming Byzantium upgrade.

A zero-knowledge succinct non-interactive arguments of knowledge, or zkSNARK, is used to prove that data is valid without actually revealing what that data is. The technology sits at the heart of the zcash network, and recent months have seen developers moving to integrate the privacy tech into ethereum.

Earlier today, the zkSNARK part of a zcash transaction was verified on the Byzantium testnet. While only a trial, the development is a critical step toward bringing that kind of functionality to the public ethereum network.

As previously reported, testing on Byzantium is expected to continue into October. Byzantium's formal introduction will then introduce the gas-subsidised pairing checks and elliptic curve operations that make this kind of verification possible.

This means that once Byzantium becomes the law of the land, a cryptographically privatized transaction can be verified on the network. 

However, computations for zkSNARKs are costly. The transaction, which is viewable on the test network here, cost a total of 1,933,895 gas. To put this in some context – a non-private transaction currently costs around 21,000 gas, tiny compared to the zcash equivalent.

Beyond the verification, there is still work to be done before private transactions are possible on ethereum.

Christian Reitwiessner, leading zkSNARKs developer for ethereum, told CoinDesk:

"What is missing after that is basically everything that was missing on top of the Ethereum Virtual Machine in the early times of Ethereum: We need practical implementations of all the other components of a zkSNARK system (apart from the verification)."

Disclaimer: CoinDesk is a subsidiary of Digital Currency Group, which has an ownership in the Zerocoin Electric Coin Company, developer of zcash.

Image via Shutterstock

DISCLOSURE

Please note that our privacy policy, terms of use, cookies, and do not sell my personal information has been updated.

The leader in news and information on cryptocurrency, digital assets and the future of money, CoinDesk is a media outlet that strives for the highest journalistic standards and abides by a strict set of editorial policies. CoinDesk is an independent operating subsidiary of Digital Currency Group, which invests in cryptocurrencies and blockchain startups. As part of their compensation, certain CoinDesk employees, including editorial employees, may receive exposure to DCG equity in the form of stock appreciation rights, which vest over a multi-year period. CoinDesk journalists are not allowed to purchase stock outright in DCG.


Learn more about Consensus 2024, CoinDesk’s longest-running and most influential event that brings together all sides of crypto, blockchain and Web3. Head to consensus.coindesk.com to register and buy your pass now.