Cointime

Cointime

Download App
iOS & Android

Optimistic vs. Zero-Knowledge Rollups: What’s the Difference?

TL;DR

The increasing popularity of crypto and blockchain has led to developers seeking a way to scale by improving a system’s ability to accommodate the growing demand. Sharding, sidechains, state channels, and rollups are some approaches to scaling. Blockchain rollups offload certain transaction processes to a secondary chain while storing transaction data on the main Layer 1 blockchain. In this article, we explore the two types of rollups in the crypto space – optimistic and zero-knowledge.

Introduction

Due to rising crypto demand, some blockchains’ abilities are tested to their limits. This could lead to network congestion and expensive transaction costs. To address this, scaling solutions are being developed and tested to increase transaction throughput and speed. Such solutions can be categorized into two groups: Layer 1 and Layer 2.

Layer 1 scaling solutions like sharding make changes directly to the main blockchain (also known as a base or Layer 1 blockchain). Layer 2 scaling solutions run on top of a Layer 1 blockchain. Examples of Layer 2 scaling solutions include state channels, sidechains, and blockchain rollups.

Blockchain rollups are protocols designed to enable high throughput and lower costs. They aim to fix the problem many popular blockchains face by bundling transactions and reducing data size for more efficient transaction processing and storage.

What Are Blockchain Rollups?

Rollups are a Layer 2 solution that bundles up transaction data and transfers it off the main chain (or Layer 1 blockchain). Transaction execution is then performed off-chain, while assets are held in an on-chain smart contract. The transaction data will be sent back to the main blockchain upon completion.

Theoretically, any Layer 1 solution can implement rollups to increase transaction efficiency in terms of throughput. With rollups, a blockchain can increase the number of transactions processed and recorded within a certain timeframe.

Presently, there are two types of rollups – optimistic rollups and zero-knowledge (zk) rollups.

What Is an Optimistic Rollup?

Optimistic rollups are protocols that increase transaction output by bundling multiple transactions into batches, which are processed off-chain. After that, the transaction data is recorded on the main chain with data compression techniques that help lower cost and increase speed. According to Ethereum, optimistic rollups can improve scalability by 10 to 100 times.

How do optimistic rollups validate transactions?

Transactions are valid by default to increase efficiency. You may wonder if this would compromise security in favor of transaction processing speeds. However, optimistic rollups use a fraud-proving scheme, with a dispute-resolution period known as a ‘challenge period.’ Within this period, anyone monitoring the rollup can submit a challenge to verify if the transaction has been processed accurately through a fraud proof.

If that batch is found to have errors, the rollup protocol will rectify them by re-executing the wrong transaction(s) and updating the block. Parties who approve incorrect transactions for execution will be penalized.

Limitations of optimistic rollups

While there isn’t a transaction validation process, there is a challenge period that zk rollups do not have, which increases the time taken for transactions to be finalized.

The finality of chains with optimistic rollups is also lower than that of zk rollups. Finality is the measure of how long a user has to wait for a reasonable guarantee that the transactions will not be reversed or altered. Withdrawals on optimistic rollups are delayed as the challenge period needs to lapse before funds can be released. In contrast, withdrawals from zk rollup take effect as soon as the zk rollup smart contract verifies the validity proof.

Some people also view optimistic rollups as less efficient than zk rollups. With optimistic rollups, all transaction data must be posted on-chain to finalize transactions. With the zk counterparts, only validity proofs are required on-chain.

What Is a Zero-Knowledge (zk) Rollup?

Zero-knowledge rollups are protocols that bundle transactions into batches to be executed off the main chain. For every batch, a zk rollup operator will submit a summary of the required changes once the transactions in the batch have been executed. Operators have an additional role in producing validity proofs to prove that the changes are accurate. These proofs are significantly smaller than transaction data; therefore verifying them is quicker and cheaper.

On Ethereum, zk rollups reduce transaction data via compression techniques when writing transactions to Ethereum as calldata, effectively reducing user fees.

How do zk rollups validate transactions?

Zk rollups use zero-knowledge proofs (ZKP) to validate transactions. ZKPs are used by someone called a prover who wants to convince another party, known as a verifier, that they possess knowledge, thereby verifying a transaction.

This is how it works:

  1. The prover provides a mathematical proof that only they can generate.
  2. The verifier uses this mathematical proof to verify the validity of the transaction.
  3. The information can receive validity proof without revealing the contents to the verifier.

Benefits of zk rollups

Zk rollups can offer a high level of security for users if implemented properly. One key feature contributing to this security is the use of zero-knowledge validity proofs. They ensure that the network can only function in a valid state and that operators cannot steal user funds or corrupt the system in any way.

Another benefit of zk rollups is that users don't need to monitor the network. Zk rollups store all data on-chain and require validity proofs. Therefore an operator can't cheat, and users don't have to worry about network misbehavior. Additionally, zk rollups let users withdraw their funds onto the mainnet without having to cooperate with operators by proving token ownership via data availability.

Similar to optimistic rollups, zk rollups also implement an off-chain execution mechanism to increase transaction execution speeds.

Differences Between zk Rollups and Optimistic Rollups

Below is a summary of the differences between optimistic and zk rollups.

What’s the Future of Zero-knowledge & Optimistic Rollups?

The future of zero-knowledge and optimistic rollups is still a question mark. As more people adopt crypto and blockchain, rollups may play a vital role in improving blockchain efficiency. Blockchains will likely continue to test various scaling solutions, including sharding, rollups, and layer 0. We could also see new solutions being created and implemented, either along with or instead of rollups.

Closing Thoughts

Since the demand for crypto has increased and stretched the limits of current blockchains, many have proposed different scaling solutions. In this article, we examined the inherent differences between two varieties of rollups, optimistic and zk rollups. As rollups continue being battle-tested, we may eventually see a superior variety that could help us reach scalability for mass adoption.

Disclaimer and Risk Warning: This content is presented to you on an “as is” basis for general information and educational purposes only, without representation or warranty of any kind. It should not be construed as financial advice, nor is it intended to recommend the purchase of any specific product or service. Digital asset prices can be volatile. The value of your investment may go down or up and you may not get back the amount invested. You are solely responsible for your investment decisions and Binance Academy is not liable for any losses you may incur. Not financial advice.

Read more: https://academy.binance.com/en/articles/optimistic-vs-zero-knowledge-rollups-what-s-the-difference

Get the latest news here: Cointime channel — https://t.me/cointime_en

Blockchain
Comments

All Comments

Recommended for you

  • Hong Kong Stock Exchange Collaborates with S&P Dow Jones Indices to Launch Co-Branded Index

    The Hong Kong Stock Exchange has announced a collaboration with S&P Dow Jones Indices to develop and launch the S&P 500 Hong Kong Stock Exchange Technology 100 Index. This index aims to measure the performance of leading companies listed in the United States as well as the largest technology companies by market capitalization listed in Hong Kong. The index is approximately 60% allocated to the Hong Kong Stock Exchange Technology 100 Index and 40% to the S&P 500 Index, with weights adjusted quarterly.

  • LeCun et al. Propose H-JEPA Hierarchical World Model for End-to-End Learning in Visual Planning

    On October 12, according to an arXiv paper, researchers Wancong Zhang, Basile Terver, Michael Rabbat, Yann LeCun, and Randall Balestriero proposed H-JEPA, an end-to-end training scheme for a hierarchical action-conditioned JEPA world model, where each layer predicts further into the future within its learned latent space. Planning is conducted top-down: the top layer optimizes the goal, and each layer's predictions become sub-goals for the layer below. When factors in the data evolve at separate time scales, higher layers discard rapid, unpredictable details while retaining slower, task-relevant states. In four simulated navigation and manipulation environments, hierarchical planning outperformed flat JEPA; in the Visual AntMaze task, a three-layer structure increased the success rate from 18% to 73%, while requiring less computational power for planning. Ablation experiments indicate that the gains come from both temporal decomposition and high-level goal representation. Under inverse dynamics supervision, this method can be scaled to real robot videos in DROID.

  • Anthropic Bans 11.4 Million Accounts in Six Months, 42000 Appeals Overturned

    On October 12, Anthropic's transparency report updated on July 23 revealed that a total of 11.4 million accounts were banned in the first half of 2026. This is significantly higher than the 1.45 million accounts banned in the second half of 2025, marking an increase of approximately 7.9 times. The statistics cover all of Anthropic's products and services without distinguishing between Claude chat and developer products. During the same period, 398,000 appeals against account bans were received, of which 42,000 resulted in overturned decisions. Based on these figures, the number of overturned bans accounts for approximately 10.6% of the total appeals. Anthropic stated that accounts may be banned for violating usage policies, terms of service, or regional support policies.

  • 2026 Nobel Prize in Economic Sciences Announced

    On October 12, the Royal Swedish Academy of Sciences announced that Robert E. Hall and Michael Woodford have been awarded the Nobel Prize in Economic Sciences. They are recognized for developing new macroeconomic models that significantly enhance the ability to implement effective stabilization policies. Based on these models, timely fiscal and monetary policy measures can reduce the peaks and troughs of the economy. Robert E. Hall and Michael Woodford received this year's award for demonstrating how to reconstruct economic models to revitalize stabilization policies. Instead of building models based on statistical relationships among macroeconomic variables such as inflation, production, and consumption, they opted to establish a foundation based on microeconomic principles. This includes understanding how the overall behavior of households and businesses influences the economy. Robert E. Hall was born in 1943 in Palo Alto, California, and earned his Ph.D. from the Massachusetts Institute of Technology in 1967. He is a professor at Stanford University in California. Michael Woodford was born in 1955 in Chicopee, Massachusetts, and earned his Ph.D. from the Massachusetts Institute of Technology in 1983. He is a professor at Columbia University in New York.

  • Amazon Plans $7 Billion Acquisition of AI Company Decart

    According to sources, Amazon is in talks to acquire the AI startup Decart, with the deal potentially valued at around $7 billion. Decart, headquartered in San Francisco, USA, has software that allows developers to switch more easily between different AI chips. As companies compete for greater computing power, this capability is becoming increasingly important. Sources indicate that if negotiations do not break down and no other bidders emerge, the deal could be finalized soon. According to private market data firm PitchBook, Decart has raised over $400 million in venture capital from investors such as Sequoia Capital, Benchmark, and Radical Ventures. In May of this year, the company's valuation was close to $4 billion.

  • Contractor for Supermicro Pleads Guilty to Illegal Transfer of Nvidia Chips to China

    Court documents reveal that a contractor associated with Supermicro has pleaded guilty to participating in a scheme to illegally transfer servers equipped with Nvidia's advanced AI chips to China. The court case records, released on October 9, indicate that external contractor Sun Tingwei (phonetic) pleaded guilty on Thursday in the U.S. District Court in Manhattan. The U.S. Department of Justice charged Supermicro co-founder Liang Yixian, Taiwan area business manager Zhang Ruicang, and Sun Tingwei in March, accusing the three of conspiring to violate U.S. export control regulations by illegally transferring approximately $2.5 billion worth of equipment utilizing U.S. AI technology to mainland China. The indictment states that the scheme began around 2024, with the three allegedly using a Southeast Asian company as a transit entity to conceal the fact that the ultimate customer was located in China.

  • Yixin Issues Apology: May Be Insolvent

    On October 12, Yixin Group published an "Apology Letter to Clients of Fixed-Income-Like Products" on its subsidiaries Ruicheng and Yirenyouxuan App. Yixin Group stated that due to the contraction of its inclusive finance and wealth management business scale and poor earnings, it has decided to completely stop the redemption of fixed-income-like products by May 22, 2026, and will strive to fairly compensate all investors through orderly exit. However, due to significant losses in multiple business areas, coupled with low asset values in market-based disposals and a lack of effective funding sources, the fixed-income-like products have effectively defaulted, for which the company sincerely apologizes to its clients. The letter indicated that after halting the redemption of fixed-income-like products, Yixin Group systematically reviewed the status of various businesses and promptly commissioned third-party institutions to conduct asset verification and financial due diligence. Preliminary findings suggest that Yixin Group may be insolvent, with a significant debt gap. The underlying assets corresponding to the unpaid fixed-income-like products are of poor quality, and efforts to seek market-based overall disposal have been unsuccessful. Legal due diligence institutions stated that they could not independently investigate the compliance of fixed-income-like products based on the transaction channels and models provided by the group. Yixin Group stated that it will further clarify its asset and liability situation, continue to stabilize its lending and other licensed businesses, make every effort to accelerate the recovery of non-performing loans, expedite the disposal and monetization of valuable assets, and communicate sincerely with clients of fixed-income-like products to resolve risks in accordance with laws and regulations, aiming for fair compensation for investors.

  • IMF Warns: AI May Have Disruptive Effects on Employment and Tax Systems

    On October 12, IMF President Kristalina Georgieva warned that AI is having disruptive effects on the labor market and tax systems, and policymakers need to rethink the education system and take immediate action to help society adapt to these changes. Georgieva stated during her debut at the IMF and World Bank Annual Meetings in Bangkok on Monday, "This is a slowly moving tsunami, but it is still a tsunami." In a session discussing the impact of AI on employment, she noted that AI has weakened demand for certain human workers by replacing a large number of repetitive, procedural jobs; at the same time, it is driving an increase in low-wage positions in industries such as construction, which she believes is "not something to celebrate." Georgieva indicated that this transformation will have profound implications for public finances, with the risk that AI may shift the economy from labor to capital, thereby undermining government tax revenues, as labor income has traditionally been a significant basis for taxation.

  • SWI Group Raises $895 Million to Transform Bitcoin Mining Facilities into AI Infrastructure

    On October 12, The Block reported that SWI Group has raised €800 million (approximately $895 million) from institutional investors following its acquisition of Genesis Digital Assets, a Bitcoin miner owned by FTX. The funds will be used to expand its AI data centers and high-performance computing infrastructure in the United States and Europe. As part of its strategic transformation, the company is repurposing suitable Bitcoin mining facilities for AI computing, gradually exiting the cryptocurrency mining business.

  • CSRC: Exploring Systems and Practices More Suitable for Innovative SMEs

    Wang Li, Deputy Director of the General Office of the China Securities Regulatory Commission (CSRC), stated at a press conference for the 2026 Financial Street Forum Annual Meeting on October 12 that over the past five years, the CSRC has solidly promoted high-quality market development. The Beijing Stock Exchange has operated safely and stably, effectively fulfilling its functions, and positive results have been achieved in market construction.

Daily Must-Read

Popular Activities

RaveDAO at Terra Solis by Tomorrowland: A Female-Led Techno Night Where Web3 Culture Converges

RaveDAO at Terra Solis by Tomorrowland: A Female-Led Techno Night Where Web3 Culture Converges

April 30 - April 30
Dubai

Popular Tags

Cointime
News
Contents
RSS
Company