Polygon Uses Zero-Knowledge Proofs in New Ethereum Virtual Machine Rollup

Polygon, one of the leading Layer 2 Ethereum scaling solutions, has unveiled an Ethereum Virtual Machine (EVM)-compatible rollup.

Dubbed Polygon Miden, the protocol uses zero-knowledge (ZK) proofs to offer enhanced privacy and EVM-compatibility on Layer 2. The protocol’s development is being led by the pseudonymous former Facebook lead zero-knowledge researcher, Bobbin Threadbear, who is known for leading the build-out of Novi’s Winterfell. Alan Szepieniec of the Nervos Foundation will also have a hand in the development of Miden’s STARK components.

The launch follows Polygon’s unveiling of a $1B fund for strategic investments into ZK-based solutions in August. Polygon also merged with ZK-based rollup Hermez that same month, before teaming up with Ernst & Young on the third version of their Nightfall protocol in September.

Polygon project describes zero-knowledge cryptography as “the most promising technology for scaling.”

ZK Technology

The project introduces Polygon’s Miden Virtual Machine, which pioneers an EVM-compatible rollup paired with zk-SNARK proofs to blister privacy.

Zero-knowledge-based protocols can verify transactions while also ensuring that no data beyond the time and date that it occurred is publicly accessible on the blockchain. Transactional counterparties are exclusively able to access detailed information relating to a specific transaction.

Polygon states that while ZK technology was “conceived in the mid-80s, it is only with the advent of blockchain that it has found a strong use case, introducing new ways to tackle some of the industry’s biggest challenges.”

Early pioneers of using zero-knowledge proofs in the context of blockchain include Zcash and later JP Morgan, both of which used zk-SNARK proofs to verify transactions. However, Binance describes zk-STARKs as “addressing many of the previous drawbacks of zk-SNARKs,” adding that STARK-based technologies are “now being touted as the new and improved version of the protocol.”

Polygon writes that while ZK rollups offer a lot of promise, the technology has not previously been shown to be effective for verifying EVM-based transactions.

Miden VM differs from existing rollup solutions by creating a STARK-based proof of execution for all programs executed on the platform. The proof “can then be used by anyone to verify that a program was executed correctly, without the need for re-executing the program or even knowing what the program was,” Polygon writes.

Polygon notes that Miden comprises “a prototype for early adopters” at this stage. “In the coming months, the plan is to develop Miden VM into a production-grade VM with unique characteristics such as multi-language support and built-in privacy,” the team added.

In addition to its native language Solidity, Polygon plans for Miden to support a variety of high-level blockchain-centric languages in the future. Miden will also be integrated with Polygon’s existing PoS, SDK, Avail, Nightfall, and Hermez.

Scaling Solutions

While Polygon first burst onto the scene with its EVM-compatible second-layer commit chain, the team’s recent investments in ZK technology and rollups evidence the project’s intent to expand its suite of second-layer scaling solutions.

In August, Polygon described zero-knowledge technology as critical to achieving its objective of onboarding one billion users. Despite the new release, Polygon emphasizes it will continue to maintain all three of its zero-knowledge-based platforms, noting its ambition to become “the industry’s leading ZK powerhouse.”

While Miden comprises Polygon’s first “STARK-only solution,” its recent acquisition Hermez is also experimenting with STARK-based technologies. After announcing its $1B zero-knowledge fund in August, Polygon revealed it would merge with ZK-rollup Hermez Network in a deal worth 250 million MATIC (roughly $250 million at the time).

The Layer 2 network was rebranded to Polygon Hermez and absorbed into Polygon’s ecosystem. The deal was described as the first successful blockchain merger and appeared to comprise Polygon’s major first foray into zero-knowledge technology. At the time of the merger, Hermez represented a total value locked (TVL) of $681,000. Its TVL has since crashed by more than 53% to sit at $318,000.

Third Iteration

In September, Ernst & Young (EY), one of the so-called Big Four professional services firms announced it had begun collaborating with Polygon to scale its Ethereum-based enterprise products.

Polygon began working with EY on the third iteration of the zk-SNARK-based scaling solution, Nightfall. The first version of Nightfall was released by EY in 2019.

EY described Nightfall 3 as combining Optimistic Rollups with zero-knowledge cryptography, suggesting the protocol inspired Miden’s design. At the time, EY wrote:

“With privacy being a fundamental requirement for enterprise use cases as well as one of the most required features by blockchain users overall, we strongly believe a solution like this is highly needed and will have a great product/market fit and adoption.”

EY also noted it is pursuing a “joint roadmap” alongside Polygon moving forward that will “prioritize the development of Ethereum-based scaling solutions and enterprise-friendly features focused on privacy innovations.”

“Special focus will be put on ZK-based technology, given its potential to support advanced use cases and regulatory compliance,” it added.