Zero-Knowledge (ZK) rollups hold long-established fundamentals but have only recently been implemented into the Web3 space. The technology behind ZK rollups — and their integration into blockchain technology — is steadily evolving alongside Web3, continuing to emerge in layer 2 (L2) blockchain.
The development of ZK Ethereum Virtual Machines (zkEVMs) has risen amid this technological evolution. This new ZK tech enables developers to port Ethereum-based decentralized applications (dApps) and tokens to the zkEVM. Many platforms are already working on growing this technology such as Optimism, Arbitrum, and Prom zkEVM.
ZK rollups explained
ZK rollups are a L2 solution that makes it possible to store and process transactional data off-chain, separate from a blockchain’s main chain, and involves submitting only proof of the transactions — not the data within. This process utilizes the cryptographic process known as ZK proofs which enable transaction verification, without revealing any transactional data.
ZK rollups are able to ‘roll-up’ multiple transactions into one batch off-chain, verify them, and then submit them on-chain all at once. This process reduces costs, improves transaction speed, and overall, reduces the pressure of Ethereum’s scalability and congestion bottlenecks.
ZK rollups in action
One of the platforms mentioned earlier, Prom zkEVM, offers a Modular L2 solution that attests to the efficiency and functionality of ZK rollups. Powered by Polygon, Prom uses ZK rollups to make multichain interoperability possible, all while ensuring privacy, minimal transactional costs, and scalability.
Using zkEVM technology, Prom demonstrates the efficiency of ZK rollups across both EVM and non-EVM compatible networks by submitting immutable transactions secured by ZK proofs. This enables multichain interoperability that is efficient, secure, and scalable without sacrificing privacy, increasing transaction costs, or contributing to network congestion.
Benefits of ZK rollups
By incorporating ZK cryptographic techniques into rollups, platforms like Prom zkEVM demonstrate the practical benefit of ZK rollups — enabling transactional validation while maintaining privacy and defending against hack/fraud attempts.
In contrast to platforms like Optimism that utilize rollup tech to reduce costs and improve scalability, the lack of ZK proof integration exposes transactions to security, privacy and centralization risks.
As opposed to traditional blockchain solutions, the use of ZK rollups enable far higher transaction volume to be handled by aggregating multiple off-chain transactions. Through batch processing — and the single-proof submission of that batch to the blockchain — ZK rollups drastically reduce the on-chain data workload. This leads to not only decreased gas-related fees, but ultimately, significantly higher transactional throughput.
Furthermore, by maintaining the privacy and security of transactional data, ZK rollups adhere to decentralized principles that underpin blockchain integrity. Utilizing a consensus mechanism for transactional proof verification and finality, ZK rollups remain decentralized autonomous organization (DAO) centered.
ZK rollups: SNARKs vs. STARKs
There are two types of ZK proofs most commonly employed in the process of ZK rollups, each with their own distinct purpose, advantages, and disadvantages:
zk-SNARKs (ZK Succinct Non-Interactive Argument of Knowledge):
SNARKs are a type of ZK proof that requires minimal computational power to verify while generating only very small transactional proofs.
Although they are efficient in both processing speeds and data size efficiency, they do require a trusted setup that can be compromised if its parameters are jeopardized. If the initial parameters are compromised, the security of the entire system is put at risk.
zk-STARKs (ZK Scalable Transparent Arguments of Knowledge):
STARKs are nearly the opposite to SNARKs, in that they do not require a trusted setup and are able to generate large proof sizes.
Although they eliminate the security risk of SNARKs and accommodate larger proofs, they feature slower verification time and far higher computational power to batch transactions together off-chain. This makes them more applicable to larger scale enterprises that don’t primarily focus on the protection of privacy.
ZK rollups: A developing technology
ZK rollups are still a developing technology within the L2 space and despite the advantages they pose, there are still challenges ahead. Due to the computational requirements necessary to employ and maintain them, the nature of ZK rollups make them heavily resource-reliant and their implementation complex.
However, cryptography, cryptographic tools, and overall adoption of such techniques are only continuing to grow. This growth is revealed through the increased familiarity of ZK proof techniques by developers and the wider recognition for privacy in the Web3 space to adhere to decentralized principles.
As L2 solutions like Prom zkEVM continue to demonstrate how efficient the use of ZK rollups can be, ZK rollup adoption is expected to only accelerate as Web2 transitions to Web3.
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