Foresight Ventures: All about Polygon zkEVM and zkEVM Rollup

  • Storage: via statelessness and enshrined zkEVMs
  • Compute: via enshrined zkEVMs

0. zkEVM

a) Intro to zkEVM

Before we can understand how zkEVM Rollup innovates Ethereum user experience, we need to understand the concept of zkEVM. If you want to learn more about zk, zkVM and zkEVM, feel free to read our previous research article.

  • EVM: the smart contract execution environment of the Ethereum ecosystem. It is the existence of EVM that makes Ethereum capable of running smart contracts and becoming a global computing network (compared to Bitcoin, which is probably only counted as a calculator), and it also gives rise to the concepts of EVM compatible, EVM equivalent, EVM superset.

b) Meaning of zkEVM

  • For DApp developers: Developers can use zkEVM to give zk superpowers to any smart contract without learning any zk-related hardcore knowledge or new languages other than Solidity or maybe Vyper.
  • For zkEVM developers: Instead of writing different circuits for the smart contracts on the network, they can simply maintain zkEVM.
  • For Layer3 builders: You can try to build Layer3 Verifier in zkEVM, so that Layer3 batch transactions can be proven “off-rollup” and packaged into a single tx on the main network (L3: 1000 tx → L2: 10 tx → L1: 1 tx), enabling App-rollup.
  • For Ethereum: the existence of multiple zkEVM schemes will eventually become important public goods, helping Ethereum to achieve the next stage of Enshrined zkEVM and zk everything Roadmap.

c) zkEVM Solution and their Progress

The zk Rollup project has been very active lately. StarkNet announced a future token offering, Aztec released a privacy DeFi, zkSync released a countdown to the mainnet launch, Scroll released a Pre-Alpha version of zkEVM, and Polygon open-sourced their source code……

  • Compiler-based: StarkNet, zkSync, OlaVM, etc. This is the track with the most players, but it actually varies a lot from project to project.
  • Type 2: Fully EVM-equivalent zkEVM, with slightly different internal structure. Such as the future Scroll and Hermez.
  • Type 2.5: EVM-equivalent zkEVMs with only different gas costs (which may lead to minor compatibility differences). e.g. Scroll and Hermez with precompiles for complex operations.
  • Type 3: zkEVMs that are almost EVM equivalent. e.g. Scroll and Hermez at this stage.
  • Type 4: EVM-compatible zkEVM at the language level, with different features and developer toolings, and developers cannot write bytecode directly. e.g. zkSync and StarkNet.
  • Compatibility (DApp developers, infrastructure, development tools, miners)
  • Development Difficulty (maintenance difficulty, development progress, system complexity, engineering implementation complexity)
  • zkSync: zkEVM at IR level (the LLVM-IR part). Good compatibility (language level), medium performance and development effort, more flexible. The highlight is the ability to support languages other than Solidity via LLVM after compiler iterations.
  • Hermez and Scroll: both are considered zkEVM at the Bytecode level (does not means have to be an exact reuse of EVM Bytecode, but the differences of them are subtle). Compatibility is excellent, performance is sacrificed (the original EVM is not zk-friendly, and there are many performance challenges to overcome after “circuitization”). Development is difficult. The best part is that the architecture is secure and most native.

1. Polygon zkEVM Rollup

The core component of Polygon Hermez’s open source zkEVM Rollup network is zkEVM. Its overall technical solution compares favorably with other solutions and is essentially the same as described in our previous article.

a) Polygon zkEVM Rollup Architecture

The overall architecture of the Polygon zkEVM Rollup is as follows:

  • zkProver: zkProver is the software that any miner who wants to participate in the Polygon zkEVM Rollup network as an Aggregator needs to run. As the name implies, zkProver is a prover that generates zk proofs. Essentially, zkEVM is a polynomial representation of state transitions, and zkProver contains a Main SM Executor and several Secondary State Machines to generate proofs for the state transitions.

b) Polygon zkEVM Rollup Design

The core idea behind Polygon zkEVM Rollup’s design is:

  • No access (anyone can participate in the network, as Sequencer or Aggregator)
  • Security (Inherits the security of Ethereum, helping to verify Rollup state updates and proofs through the Ethereum network)

c) Polygon zkEVM Rollup Advantages

There are a number of advantages that really make Polygon’s solution stand out.

2. zkEVM Rollup’s Strength

a) Layer 1 vs Rollup

Users have been suffering from Layer 1 gas for a long time, and in our previous MEV study, the model of an ideal network was discussed.

  • no spam
  • very low fees
  • decentralized with no permission and no censorship
  • scalable with general computation

b) Optimistic Rollup vs zk Rollup

In the long term and with realistic theoretical performance limits, zk Rollup is more scalable than OP Rollup, with stronger security assumptions.

c) zk Rollup vs zkEVM Rollup

If zk Rollup, then why is Optimistic Rollup the more popular one now?

3. UX of zkEVM Rollup

a) The Right Time, Place and People

The emergence of zkEVM Rollup is the right time and the right place:

  • Place: The security and social consensus provided by Ethereum provided the perfect ground for the establishment of zkEVM Rollup.
  • People: The EVM ecosystem dominates blockchain development, and numerous zk development teams are contributing to the zkEVM solution.

b) UX for Developers

  • zkEVM ⇒ No need to learn a new language or even write a new contract to develop a DApp: Solidity is the number one language in the blockchain contract world, with countless resources and great ecosystem, and is the most suitable language for blockchain scenarios, the combination of these two advantages is far better than Move or Rust etc.
  • Rollup ⇒ Unlock more application scenarios: Using the Ethereum mainnet for applications such as payments or games is not suitable due to performance and cost issues. zkEVM Rollup allows more apps to be implemented as DApps.

c) UX of Users

  • zk ⇒ Stronger security than PoS networks and faster finality than OP Rollup: Some PoS networks rely on staking for security, but their small capitalization creates weak security guarantees. zk’s cryptography guarantees absolute security through mathematics. OP Rollup’s challenge period prevents a tx from being confirmed for a certain period of time, while zk Rollup’s proof of a tx confirms the tx once it is generated.
  • EVM ⇒ Exactly the same usage process and infrastructure: Except for the need to switch networks within the wallet and application, all user usage processes will be exactly the same as on the main network, with no additional learning costs, just use the application as before.
  • Rollup ⇒ OP and zk Rollup both offer L2 instant finality: in terms of user experience, the transaction is executed before the user is even aware of it. So the user does not have to wait for 10 seconds or 10 minutes to send the next transaction. In terms of application usage, users can carry out on-chain activities, high-frequency transactions or on-chain games, etc. in a more hassle-free way.

d) UX of Polygon zkEVM Rollup

In the future, the experience of users and developers on zkEVM Rollup will be infinitely similar to that of the main net, and will be even faster and smoother with the advantages of low gas and fast confirmation.

  • Better experience: ETH as a Rollup token allows L1 users or cross-chain bridge projects to avoid the extra Swap step in the process (most will cross ETH directly). ETH is also more orthodox as a gas.
  • More significant differentiation: The Polygon zkEVM Rollup will be more distinctly different from the Polygon PoS, and the difference in mechanics does require such a difference to allow users to choose a solution that suits them better.

4. The Future of zkEVM Rollup

For the future of the zkEVM Rollup solution, we will analyze the technical future, and what the end game of the solution will be.

a) zkEVM Tech

Vitalik has very deep insights on this topic. Among the four classifications of zkEVM he outlined, there is no real good or bad solution, just different technical trade-offs: closer to the low-level but development progress will be slower, less compatibility but development progress will be faster.

b) Rollup Tech

The endgame of Rollup technology will be zkEVM Rollup, while Optimistic Rollup will continue to have its own place, and there will even be a hybrid of zkEVM and Optimistic Rollup (personally, I think one mechanism is sufficient).

c) Tech…is not the most important

We talked a lot about technology, but technology is certainly not the most important thing. The bottlenecks in zkEVM Rollup, Rollup, Ethereum, and even blockchain are never technical bottlenecks in engineering implementation or DA or consensus, but users.

d) End Game

So what do we imagine a true endgame zkEVM Rollup would look like?

  • Rollup level: Ensure that the core values of the blockchain (decentralization, security) are prioritized, instead of an arms race for TPS.
  • Developer level: EVM compatibility is not the deciding factor. It’s which zkEVM Rollup can reach the fastest developers and get them to use it as a network for development. It is never about the network conforming to the developer, but rather about the developer picking the fastest or best network overall, and then slowly adapting to that network’s development.
  • User Level: The mindset and social consensus of users is very important. In addition to the Reach developers, the most important factor is who is the first and most effective Reach to the users. A successful network should not become a technical geek’s ego about the superiority of a technical solution, but a real solution that creates value for users.

Related Links



Foresight Ventures is a blockchain technology-focused investment firm, focusing on identifying disruptive innovation opportunities that will change the industry

Love podcasts or audiobooks? Learn on the go with our new app.

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store
Foresight Ventures

Foresight Ventures


Foresight Ventures is a blockchain technology-focused investment firm, focusing on identifying disruptive innovation opportunities that will change the industry