Cronos: ZK-Rollups Solve Cross-Chain Bridge Security Issues

Cronos Labs’ Ken Timsit explains why the firm is towing the ZK path as it expand to the Ethereum ecosystem.

Developer coding security for Crono's.
Created by Kornelija Poderskytė from DailyCoin
  • The trusted cross-chain bridge model has posed a significant security concern in recent years.
  • Head of Cronos Labs Ken Timsit has tipped ZK-rollups as the solution to cross-chain security issues.
  • The statement comes as the firm prepares to launch a ZK-powered Ethereum Layer 2.

The problem of fragmented liquidity and assets across blockchains has led to the proliferation of several bridging solutions to allow users to move assets between typically isolated blockchains. In recent years, however, these would-be crypto-armored trucks have proven a significant security risk, serving as easy and ideal targets for bad actors due to the substantial funds they typically hold. 

While bridges have several attack vectors, most agree that the trust-based model of existing bridges requiring a centralized entity or a small set of network participants to attest to the validity of information passed across chains is the leading cause of attacks. The apparent alternative to existing solutions is a trustless model. However, this alternative has proved costly and computationally impractical up to now. 

With marked progress in zero-knowledge technology and ZK-proof generation, builders are increasingly optimistic that the anxiety users face when bridging assets across blockchains could soon become a thing of the past. 


In an exclusive interview, Cronos Labs‘ head Ken Timsit spoke with DailyCoin Journalist David Okoya about how ZK-rollups tackle cross-chain bridge security concerns. 

‘ZK Solves Cross-Chain Bridge Frustrations’

In December 2023, Cronos Labs announced the launch of Cronos zkEVM, an Ethereum Layer 2 chain based on Matter Labs’ ZK Stack, in public testnet—the first hyperchain, as rollups based on the ZK Stack are called, to roll out to the public.

When asked about why Cronos Labs opted to build a ZK-powered rollup instead of an Optimistic rollup, Timsit contended that the deciding factor was the ability of ZK-rollups to tackle “one of the great sources of frustration” that crypto projects have faced in recent years.


“In the end, the main reason we're interested in ZK-rollups is that they solve one of the great sources of frustration we have had over the years, which is the lack of security of cross-chain bridges.”

Whereas other attempts at creating trustless bridges have required the capital and cost-intensive process of individually verifying validator signatures from the source chain, ZK technology dramatically simplifies the process by enabling the target chain to verify only a single ZK-proof, showing that validator signatures are credible.

In the case of Cronos zkEVM, security guarantees are further heightened by the fact that ZK Stack chains will be significantly compatible as they share the same zkEVM engine, a fact highlighted by Timsit.

"What's very interesting about ZK-rollups is the fact that we can have multiple Layer 2s who share the same zero-knowledge circuits, and because they share circuits, they're able to prove to each other that a cross-chain transfer or that an action has taken place across multiple chains without having to go via Ethereum and without having to rely on third party bridge operators, which have experienced many security incidents in recent years," he explained.

These security considerations are important, as Timsit explained with the example of Cronos zkEVM, a DeFi-focused chain serving as an avenue for homegrown DApps to tap into Ethereum’s thriving ecosystem and deep liquidity.

How Cronos zkEVM Stands Out

As a ZK Stack chain, Cronos zkEVM would leverage Matter Labs’ Boojum prover, which can run on GPUs of just 16GB. The chain will also benefit from zkSync’s native account abstraction, allowing DApps to simplify user experiences. Beyond these shared features among hyperchains, however, Timsit suggested that Cronos zkEVM had several stand-out features to bring to the Ethereum Layer 2 space. 

Discussing how Cronos zkEVM differed from other Layer 2 chains, Cronos Labs’ Timsit tipped Cronos’ partnership with and its ecosystem of “high quality” DApps as differentiating factors. 

“The two main points of differentiation are, number one, the partnership with and the regulated access to the banking system, and number two, the high quality of decentralized applications that we've been able to develop on Cronos through our selection through our support to developers, and through our advice to developers and we think that those points of differentiations are particularly relevant for mainstream users who are coming back into crypto right now,” he noted.

Some of the projects highlighted by Timsit included Fulcrom, a perpetual trading platform with $8.2 million in TVL per Defi Llama data at the time of writing, and Veno, a liquid staking protocol with a TVL of $17.54 million.

Beyond the Cronos zkEVM, Timsit teased that Cronos was exploring intersections between blockchain and AI. He championed a future with greater integration between both technologies when asked about his long-term thoughts on DeFi.

"When it comes to the Cronos accelerator program, which is one of the programs that we have for developers, we have started to put a lot of focus on AI, and the cohort that is currently running is in partnership with AWS And Google Cloud having a focus on how to integrate AI and blockchain technology," he revealed.

Including the Cronos zkEVM, the Cronos ecosystem now boasts three blockchains. The other blockchains include the Cosmos-based EVM-compatible Cronos Chain, which is ranked as the 37th largest blockchain by market capitalization with $3.7 billion, according to CoinMarketCap data at the time of writing, and Cronos PoS, a low-cost payments-focused blockchain.

On the Flipside

  • Few trustless bridges are available in practice due to the complexity of the technology.
  • Cronos zkEVM faces competition from other centralized exchange-backed rollups like Base and OpBNB.

Why This Matters

In recent years, cross-chain bridge security has been a significant pain point for the crypto industry, costing billions of dollars in user funds. The statements from Cronos Labs’ Ken Timsit add to the growing sentiment that these concerns could soon be a thing of the past.

Read this for more on Cronos:

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This article is for information purposes only and should not be considered trading or investment advice. Nothing herein shall be construed as financial, legal, or tax advice. Trading forex, cryptocurrencies, and CFDs pose a considerable risk of loss.

Okoya David

David Okoya is a crypto news reporter at DailyCoin based in Nigeria. He covers various topics related to the cryptocurrency industry, including exchanges, regulations, and price movements, and strives to bring fresh angles to breaking news. With experience as a freelance crypto news writer, David upholds the highest journalistic standards, telling complete stories and answering lingering questions whenever possible.