Rollup
Optimistic dan ZK
Rollup adalah pelajaran Web3 & DApp Development Fundamentals gratis di CoddyKit. Ini adalah pelajaran 2 dari 4. Kamu bisa membaca pelajaran lengkapnya di bawah secara gratis — lalu praktikkan langsung di browser dengan editor kode bawaan dan tutor AI 24/7. Ini adalah bagian dari jalur belajar Web3 & DApp Development Fundamentals, dan progresmu tersinkronisasi di web dan aplikasi CoddyKit. Kursus Web3 & DApp Development Fundamentals mencakup 4 pelajaran total.
Bagian dari pelajaran ini belum diterjemahkan dan ditampilkan dalam bahasa Inggris.
What Is a Rollup?
A rollup executes transactions on a Layer 2 and posts the transaction data (and a state commitment) back to Layer 1.
The L1 stores enough information to reconstruct and verify the L2 state, which is what gives rollups their security.
Two Main Types
There are two dominant rollup families:
- Optimistic Rollups — assume transactions are valid, allow challenges
- ZK Rollups — prove validity with cryptographic proofs
They differ in how they convince L1 the L2 state is correct.
Optimistic Rollups
Optimistic rollups assume every batch is valid by default — hence optimistic.
They post the new state to L1 without proving it immediately, relying on the threat of fraud proofs to keep operators honest.
Fraud Proofs and the Challenge Window
After a batch is posted, a challenge window (often ~7 days) opens. Anyone can submit a fraud proof showing the batch was invalid.
If a valid challenge succeeds, the bad batch is reverted and the dishonest operator is penalized.
post batch -> 7-day challenge window
no valid challenge -> finalized
valid fraud proof -> batch revertedWithdrawal Delays
The challenge window means withdrawing from an optimistic rollup back to L1 takes time (often a week).
Liquidity providers offer instant withdrawals for a fee by fronting the funds during the wait.
ZK Rollups
ZK rollups generate a cryptographic validity proof (a zero-knowledge proof) for each batch.
L1 verifies the proof mathematically, so there is no need to trust the operator or wait for a challenge period.
Validity Proofs
A validity proof (such as a SNARK or STARK) demonstrates that the new state was computed correctly from the old state and the transactions.
If the proof verifies, the state is definitively correct — no challenges needed.
proof = prove(oldState, txs, newState)
L1.verify(proof) == true
-> newState accepted instantlyFaster Finality on ZK
Because ZK proofs are verified immediately, ZK rollups offer fast finality and quick withdrawals.
The trade-off is that generating proofs is computationally expensive and historically harder for general smart contracts.
Optimistic vs ZK Trade-offs
Comparing the two:
- Optimistic: EVM-compatible, cheaper proving, slow withdrawals
- ZK: instant finality, fast withdrawals, complex proving
Both post data to L1, so both inherit Ethereum security.
Data Availability
Rollups must publish transaction data so anyone can reconstruct the state — this is data availability.
Posting data to L1 (calldata or blobs) is a major cost; innovations like EIP-4844 blobs made it much cheaper.
Putting It Together
Rollups execute off-chain and settle on L1. Optimistic rollups assume validity and use fraud proofs; ZK rollups prove validity cryptographically. Data availability anchors their security.
Next we look at moving assets between layers with bridges.
Quick Check
Test your rollup knowledge.
Recap: Rollups
You learned that:
- Rollups execute off-chain and settle data on L1
- Optimistic rollups use fraud proofs + a challenge window
- ZK rollups use validity proofs for instant finality
- Data availability on L1 anchors security
Next: bridging assets between layers.
Pertanyaan yang Sering Diajukan
Apakah pelajaran “Rollup” gratis?
Ya — teks lengkap “Rollup” gratis dibaca di sini di web. Untuk praktiknya secara interaktif (editor kode bawaan dan tutor AI 24/7) dan buka sisa kursus Web3 & DApp Development Fundamentals, upgrade ke CoddyKit PRO. Kursus Web3 & DApp Development Fundamentals mencakup 4 pelajaran total.
Apa yang akan aku pelajari di “Rollup”?
Optimistic dan ZK Kamu berlatih Web3 & DApp Development Fundamentals dengan kode praktik yang langsung kamu jalankan di browser, dan tutor AI 24/7 menjawab pertanyaanmu saat kamu mengerjakan pelajaran ini.
Apakah aku perlu pengalaman untuk memulai Web3 & DApp Development Fundamentals?
Tidak diperlukan pengalaman sebelumnya. Web3 & DApp Development Fundamentals di CoddyKit dirancang untuk pemula hingga pelajar tingkat lanjut, jadi kamu bisa memulai di sini atau dari awal dan belajar sesuai kecepatan kamu sendiri. Ini adalah pelajaran 2 dari 4.
Berapa lama pelajaran “Rollup” memakan waktu?
Sebagian besar pelajaran CoddyKit memakan waktu sekitar 5–10 menit. Setiap pelajaran ringkas dan interaktif, jadi kamu membuat kemajuan stabil dan melanjutkan dari tempat kamu tinggalkan di web dan aplikasi.
Bisakah aku menulis dan menjalankan kode dalam pelajaran Web3 & DApp Development Fundamentals ini?
Ya. Setiap pelajaran Web3 & DApp Development Fundamentals menyertakan editor kode bawaan, jadi kamu menulis dan menjalankan kode nyata langsung di browser dan mendapatkan umpan balik AI instan — tidak diperlukan penyiapan lokal.