Launch of Polygon’s zkEVM Weeks Away

The launch of Polygon’s zkEVM main net will be on March 27. According to Polygon, it will be the first ‘fully EVM equivalent’ zero-knowledge rollup to reach Etereum main net. The zkEVM will be an essential tool to onboard large numbers of users and provide the privacy that is so vital to the future of blockchain adoption.

Let’s start with some background. Since Ethereum is secure BUT expensive and slow, many projects besides Polygon have been working for years on building ‘rollups’. So-called zero-knowledge (zk) rollups generate proofs that a batch of transactions is valid, without sharing details about the transactions. By relaying these to the Ethereum Network as a single, bulk transaction, it saves up space on the Ethereum base chain AND it is good for privacy. Also, it is much cheaper: the gas fee for the bulky batch of transactions is higher than an ordinary transaction but can be shared by a large number of participants.

What Are Zero-Knowledge Proofs?

Zero-knowledge proofs are, broadly speaking, a way of proving to someone that you have certain data without revealing the data themselves. We could use some of that in our online lives! Frankly, the current state of online authentication is a mess. Every year, millions of passwords and other user data are stolen from company databases.

But basic privacy is also sorely lacking in the broad crypto space. Pseudonymous transaction data are visible on-chain. If you send me some ETH, you can see the amount of ETH I hold! Of course, there are exceptions, such as a privacy coin like Zcash, which makes use of zk-technology. Another example of a project that implements zk-tech is a coin mixer like Tornado Cash.  

With zk technology, we can envision an online world where I can prove to you that I have sufficient funds to pay you – without you having to peek in my balance. Another example I want you to be able to verify that I’m an inhabitant of the EU, without me having to reveal my exact address.

Practical Use Case: Polygon ID

Polygon ID is an important tool in Polygon’s toolkit and one of the reasons it realized it had to build out its zkEVM. Why? Polygon ID is an identity platform for DeFi and decentralized application economies. It gives users greater privacy and sovereignty while accessing Web3. 

Imagine logging in with Polygon ID, instead of logging in with Google. Unlike Google, Polygon can’t lose your password: after all, they have zero knowledge! So, with Polygon ID, you own your data and nobody else.

For Polygon ID to be able to welcome great numbers of users, it must sit on top of a highly scalable blockchain that is also decentralized and battle-tested enough for users to feel safe. And that’s why Polygon wanted compatibility with Ethereum (EVM compatibility) instead of simply building a standalone blockchain.

What Is New? EVM Compatibility

So, what is new? First, back to zero-knowledge rollups: these already existed. We could already roll up a batch of transactions and deploy a zk-proof to verify these on Ethereum. 

What’s new is the fact that these rollups on Polygon will soon be compatible with the Ethereum Virtual Machine (EVM). Think of the EVM as the computer running the Ethereum network. Compatibility with the programming language of this computer is what matters. It’s because of the compatibility of the upcoming zkEVM with Ethereum’s virtual machine that ‘developers can copy-paste code that works on Ethereum and use it to build on Polygon zkEVM without having to change a thing’.

Hence: ‘Ethereum, we complete you’, the catchphrase Polygon used to describe their philosophy.

Trade-offs Reconciling Zk-rollups with the EVM

Various projects take different approaches trying to integrate zero knowledge tech and EVM. That is because there are trade-offs. The EVM wasn’t initially designed with ZK scaling in mind. So, the zkEVM has to ‘distance itself’ enough from the EVM to create efficiencies of scale. At the same time, it can’t distance itself too much, otherwise, the compatibility is jeopardized. Polygon’s solution is a ‘Type 2’ equivalency, according to Vitalik’s classification of zkEVM’s, just like the projects from ConsenSys and zkEVM (the latter being the name for a particular project, not the category name). Type 2 zkEVMs… “strive to be exactly EVM-equivalent, but not quite Ethereum-equivalent. That is, they look exactly like Ethereum “from within”, but they have some differences on the outside, particularly in data structures like the block structure and state tree.”

Facts About the Test Phase

Polygon sums up some interesting facts about the test phase, which took place on public testnets over the past six months.

• Over 84,000 wallets have been onboarded
• Proof generation time is down to two minutes
• Average gas fee for generating proof for a large batch of transactions: $0.06

Competing ZkEVM’s: Where to Invest?

Even though the launch of Polygon’s zkEVM is only weeks away, it is not the only game in zk town: a race is on to launch zkEVMs. A good development if we want to scale Ethereum and bring Web3 to the masses.

Several zkEVMs are actively developing toward mainnet. Many are already on testnet. ZkSync, ConsenSys, and Scroll are targeting a main net launch in the first half of 2023. 

As Polygon prepares to launch its zk network, MATIC has been pumping. The zero-knowledge narrative has substance and has gained traction. And because there are no tokens for zkSync and Scroll, MATIC is the main beneficiary of the hot zkEVM narrative.