zkSync: How do zkRollups work?
What is zkSync?
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.
Extremely low transaction fees
~1/100th of mainnet costs for ERC-20 tokens and ~1/30th for ETH transfers
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
Take imToken for example, first download and install imToken (https://token.im/ ) and create/import an identity wallet.
How to use zkSync with imToken?
Open imToken's ETH wallet, then go to "My Profile" - "Explore" and enable the Layer 2 function.
Click "Deposit" to top-up your assets from Ethereum mainnet to zkSync. After the deposit is done, you can make fast and low-cost transfers via the zkSync wallet.
Learn more: How to use zkSync with imToken?
Other wallets that support zkSync
In order to scale Ethereum to accommodate a growing number of users, developers have proposed 2 solutions, namely, layer 2 and sharding (a layer 1 scaling solution).
Layer 1 refers to the Ethereum blockchain itself, and layer 2 is a network or technology that operates on top of Ethereum to improve its scalability and efficiency.
Mainstream layer 2 solutions include ZK Rollup, Optimistic Rollup, Plasma, State Channels, Validium, etc.
ZK stands for Zero Knowledge, which means that a prover can convince a verifier that an assertion is correct without providing any useful information to the verifier.
Rollup is a collective term for solutions designed to improve the performance of the Ethereum mainnet by handling transactions off-chain while keeping part of the data of each transaction on-chain.
ZK Rollup = Roll Up Transaction + Zero Knowledge Proof (zk-SNARK)
In a nutshell, ZK Rollup is a L2 scaling solution in which all funds are held by a smart contract on the mainchain, while computation and storage are performed off-chain. For every Rollup block, a state transition zero-knowledge proof (SNARK) is generated and verified by the mainnet contract.
Matter Labs, the development team behind zkSync, is an engineering team passionate about liberty, blockchain and math. Their head office is in Berlin, but they work across the globe (mostly Europe).
Matter Labs scales Ethereum with zero-knowledge proof technology with the mission to accelerate this ongoing financial revolution.
zkSync Block Explorer
zkSync Block Explorer is an open source web tool that stays synchronous with the zkSync network and allows you to view information about blocks, transactions, state root hashes, account addresses on zkSync.
The project's roadmap is planned for scalable payments, smart contracts, privacy, and censorship resistance.
Scalable payments: zkSync is currently working to build a secure and scalable digital asset payment solution.
Smart contracts: zkSync will introduce efficient, secure, Turing-complete, multilingual smart contracts in Zinc and Solidity. Learn more
Privacy: At the moment, all transactions in zkSync, just like in Ethereum, are transparent. The team plans to enable privacy in the future.
Censorship Resistance: A common problem with scalable solutions is that most users cannot participate in validation and the network tends to be centralized. zkSync intends to tackle this issue by introducing an independent consensus mechanism with two different roles: Validators and Guardians.
zkSync also plans to launch their token in the future.