As the focus turns toward web3, scalability is becoming a challenge for blockchain networks, preventing them from matching traditional financial systems. 

Advanced cryptographic techniques, such as zero-knowledge proofs (ZKPs) and scaling solutions like ZK rollups, are emerging as key solutions. 

Zk rollups involves bundling thousands of transactions off-chain, reducing the main blockchain’s data load while offering a high level of privacy and faster finality times.

Experts like Vitalik Buterin believe it could become central to blockchain scalability strategies. The Ethereum co-founder has penned several pieces explaining his vision about rollups to scale Ethereum, which has been plagued by network congestion and growing costs.

Buterin specifically endorses Zero-Knowledge Rollups due to their potential for higher throughput and immediate transaction finality.

Other industry experts like Eli Ben-Sasson of StarkWare, Alex Gluchowski of zkSync, and Barry Whitehat from the Ethereum Foundation also champion zk-rollups for their scalability and security benefits.

But are ZKPs the final piece of the scalability puzzle?

According to Mike Voronov, Head of R&D at Fluence, the answer is a bit more complex than that. 

Speaking to crypto.news Voronov acknowledged the advantages of this approach, such as “stronger security guarantees” and “shorter withdrawal periods.” However, he added that, like other scaling methods, it has its “own set of pros and cons.”

In ZKPs, the proof generation and verification process is computationally intense due to the need to execute intricate cryptographic algorithms. These algorithms ensure the proofs are both secure and concise, which is crucial for maintaining transaction privacy on blockchain networks.

“It cannot be universally said that ZKPs are the ultimate solution in every possible situation […] not to mention the higher complexity involved in researching and implementing ZK protocols.”

Voronov pointed out that other approaches, specifically fraud proofs, offer a comparable balance of performance and security. 

Fraud proofs in Optimistic Rollups allow users to validate off-chain transactions by challenging suspicious ones. Once challenged, the invalidity of these transactions is established on the main chain, ensuring security through post-verification.

This approach is less resource-intensive compared to ZKPs because it only processes computational checks when a transaction is specifically challenged rather than verifying every transaction proactively.

However, he added that the strength of ZKPs lies in their cryptographic guarantees, which is something Optimistic Rollups lack due to their reliance on fraud proofs.

“Compared to other scalability solutions such as optimistic rollups, sharding, fraud proofs, and state channels, ZKP-based solutions usually provide much stronger cryptographic guarantees and impose a lower economic and infrastructure burden on-chain.”

Francisco Leal, CTO of Talent Protocol, concurred, adding that the success of recent ZK-focused projects like zkSync and Starknet indicate that “ZK technology is already highly mature and promising.”

“Different systems have different needs, making it improbable for a single solution to universally address all use cases. Thus, diversity in scaling solutions is likely to persist, mirroring the varied demands of different blockchain applications,” Leal told crypto.news.

According to the CTO, Optimistic rollups are currently the biggest competition for ZK rollups. He pointed out that zero-knowledge proofs (ZKPs), specifically zk-SNARKs and zk-STARKs, are at a disadvantage due to their computationally intensive nature and growing demands for proof generation and verification.

Nevertheless, with the advancements in computational power, Leal expects this to “diminish” soon.

Investor enthusiasm for zero-knowledge technologies has surged, resulting in multi-million dollar investments. Key contributions include StarkWare, securing $100 million at a valuation of $6 billion, and zkSync, which raised $200 million. 

Meanwhile, Polygon Labs notably escalated its commitment to zero-knowledge initiatives, injecting $1 billion into the sector.

When asked whether or not ZK rollups could help blockchain networks scale at a level that would match or surpass their traditional counterparts, both the execs remained optimistic.

Voronov stressed that such a feat would require the “full standardization of Zero-Knowledge Proof (ZKP) protocols and associated tools.” Meanwhile, Leal emphasised that the “efficiency of proof generation and verification” currently acts as a “bottleneck” and needs improvement.