zkSync Era Architecture

What zkSync Era Is

zkSync Era is a zero-knowledge rollup launched in March 2023 by Matter Labs. It compresses many L2 transactions into a single ZK proof that Ethereum verifies — meaning you get Ethereum's security at a fraction of the cost. Era is part of a broader zkSync ecosystem: zkSync Lite (the original 2020 payment-only rollup, now legacy) and Era (general-purpose smart-contract rollup). When people say 'zkSync' today, they almost always mean Era.

What Makes Era Different from Optimism / Arbitrum

Optimism and Arbitrum are optimistic rollups — they assume transactions are valid unless someone proves otherwise via a fraud proof, with a 7-day withdrawal delay. zkSync Era is a ZK rollup — it generates a cryptographic proof of every batch's validity, posted to L1. The trade-off: ZK rollups have higher proving costs but allow withdrawal in hours instead of a week, and have stronger structural security guarantees.

Native Account Abstraction

Unique to Era among major rollups: every account is a smart contract by default. There are no EOAs (externally owned accounts) like on Ethereum mainnet. This means features that require ERC-4337 plumbing on other chains — paymasters, multi-sig wallets, signature abstraction — are built into Era at the protocol level. Pay gas in USDC? Built in. Use a passkey instead of a seed phrase? Built in. Era's UX advantages flow from this single architectural choice.

• ZK rollup with hours-not-days withdrawals (vs optimistic rollups' 7-day delay)
• Native account abstraction at the protocol level — no separate ERC-4337 layer needed
• EVM-compatible but not EVM-equivalent — some contracts need recompilation
• Boojum (the current prover) generates STARK-based proofs wrapped in SNARK for cheap L1 verification