ZkSync™ | Official Site

What is zkSync?

ZkSync is a trustless protocol for scalable low-cost payments on Ethereum, powered by zkRollup technology. It uses zero-knowledge proofs and on-chain data availability to keep users' funds as safe as though they never left the mainnet.

While security is our paramount priority, user and developer experience are central to zkSync design. We obsessively seek out improvements that eliminate friction and complexity in order to make zkSync the most enjoyable platform on Ethereum, for both end-users and builders. The best way to get an impression about it is to try out zkSync (opens new window)yourself — it should only take

minutes.Problems zkSync solves

Gas fees on Ethereum exceed $40M per month (opens new window). With zkSync these costs can be reduced to a small fraction.

UX-first crypto wallets like Argent (opens new window)or Dharma (opens new window)aim to provide a banking alternative to entire societies. zkSync makes this mission accomplishable.

The rise of DeFi opens many more interesting use cases. zkSync is here to unlock Paypal-scale for your project.

#zkSync features

Mainnet-level security with zero reliance on 3rd parties
ETH and ERC20 token transfers with instant confirmations and 10-minute finality on L1*; see supported tokens
Ultra-low transaction fees (~1/100th of mainnet costs for ERC20 tokens and ~1/30th for ETH transfers)
No registration is required to receive funds
Payments to existing Ethereum addresses (including smart-contracts)
Fees conveniently payable in the token being transferred
Withdrawals to mainnet in ~10 minutes*
Multisig (opens new window)support
Permissionless smart contracts (coming soon)
* Currently, it may take longer to fill a block with transactions. Once the block is 'sealed', it is sent to the prover and appears on L1 within 10 minutes.

#zkSync in comparison

zkSync stands out remarkably (opens new window)in security and usability among existing L2 scaling solutions. Thanks to the combination of cutting-edge cryptography and on-chain data availability, zkRollup (the core technology of zkSync) is the only L2 scaling solution that doesn't require any operational activity to keep the funds safe. For example, users can go offline for a year, then come back and be sure to safely withdraw their assets without any external help — even if zkRollup validators were long gone. At our current stage of development, we encourage users to monitor the chain for upgrades, and withdraw if they disagree with upcoming changes — in the future, upgrades will require a strict opt-in.

To quote from Vitalik Buterin's 2021 guide to rollups (opens new window):

In general, my own view is that in the short term, optimistic rollups are likely to win out for general-purpose EVM computation and ZK rollups are likely to win out for simple payments, exchange and other application-specific use cases, but in the medium to long term ZK rollups will win out in all use cases as ZK-SNARK technology improves.

Due to limitations on transaction throughput on the Ethereum Mainnet (i.e. layer 1), developers proposed layer 2 protocols to handle transactions off layer 1 so as to improve Ethereum’s performance and user experience.

zkSync is a layer 2 solution created by Matter Labs. The team solves Ethereum scalability with Rollup (i.e. one of the mainstream implementing layer 2 solutions) based on zero-knowledge proofs.

How does zkSync’s solution work?

zkSync is a L2 protocol based on ZK Rollup architecture.

ZK: Stands for Zero Knowledge.
Rollup: One of the layer 2 solutions that perform transaction execution outside the main Ethereum chain (layer 1), but post transaction data on layer 1.
ZK Rollup: ZK Rollup bundles hundreds of transfers off-chain and generates a cryptographic proof, known as a SNARK (succinct non-interactive argument of knowledge). This is known as a validity proof and is posted on layer 1.
The security of Rollup is determined by the validity and availability of data.

Validity: Ensure that the state has been verified to prevent validators from modifying data on layer 2 to steal users’ assets.
Availability: Keep data available for layer 2, ensuring that users have the data to be able to withdraw assets from layer 2 to layer 1 at any time.
zkRollup posted bundled data on layer 2 to ensure the validity and availability of data. Inheriting the security properties of layer 1, while performing execution outside of layer 1, is a defining characteristic of zkRollup.

Main features

Extremely low transaction fees
~1/100th of mainnet costs for ERC20 tokens and ~1/30th for ETH transfers
Trustless protocol
Funds are cryptographically secure, as in the Ethereum mainnet
Users are always in control of their funds
No requirement for operational activity to keep the funds safe
zkSync Wallet
Take imToken for example, first download and install imToken (https://token.im/) and create/import an identity wallet.