Rollups are a scaling solution that works by rolling-up many transactions together into a single “bunch” and then sends that “bunch” back to the consensus layer (L1) for verification. This improves efficiency by verifying multiple transactions at the same time, and also increases the number of transactions that can be verified and confirmed. There are currently two types of rollups:
Optimistic rollups
ZK-rollups
ZK rollups “roll up” transaction data into one, then each “rollup” of transactions is sent for off-chain validation, which generates a cryptographic proof (called SNARK, in the case of zkSync) that the transactions are valid. Finally, the SNARK is sent as proof of validity to the main network (Ethereum).
It is also worth mentioning that ZK rollups work due to economies of scale, where a larger number of users making transactions makes the network cheaper to use. This is the opposite of a typical blockchain, the cost of using which rises in price as network usage grows.
Optimistic rollups take a very different approach to transaction validation. Instead of proving the validity of each "pack", this technology optimistically assumes that each calculation is reliable, unless proven otherwise.
https://www.notion.so/020dd67be9e64f4f95c7e02ba9dc9a40?pvs=21
Zero-Knowledge Proofs (ZKPs) is a cryptographic technique that allows one party to prove to another that it has certain knowledge without revealing that knowledge itself. This method is attracting the attention of many blockchain researchers and developers, and here are a few reasons why many believe that the Zero-Knowledge Proofs approach is the future:
Privacy: ZKPs can maintain a high level of privacy by allowing users to confirm certain claims about their data without having to disclose that data.
Scalability: Especially in the context of zkRollups, ZKPs can significantly increase throughput and lower fees on blockchains while maintaining security at the level of the main blockchain.
Versatility: ZKPs can be integrated into many different applications, ranging from simple identity verification to complex financial transactions.
Reduce Trust Requirements: With ZKPs, you can create systems that do not need to be trusted by centralized parties or even other network participants. This could revolutionize areas such as e-voting, financial transactions, and more.
Industry Support: Leading blockchain projects are investing in the research and development of technologies related to ZKPs, recognizing their potential.
Research Progress: Over time, algorithms and protocols based on ZKPs have become more efficient and available for widespread use.
However, it must be taken into account that, like any other technology, Zero-Knowledge Proofs has its own difficulties and limitations. The main barrier to mass adoption of ZKPs at the moment is their complexity, which makes them difficult for many developers to understand and implement. However, with more investment in this area and better tools and resources, this problem can be solved.
Overall, Zero-Knowledge Proofs provide powerful tools for privacy, security, and scalability on blockchains and other decentralized systems. If their full potential is realized, they could be a key element in the future of decentralized applications and systems.
Vitalik Buterin in his articles also compares OPR and ZKR and comes to the same conclusion that Optimistic rollups (Optimism, Arbitrum) are easier to adopt and develop, so they will appear and take root faster, acquire applications and their own ecosystem (what we are now seeing ). However, technologically, in the future, ZK-rollups will surpass them. This will take more time, because. it is much more difficult to develop there, but in the end they will be much cheaper / faster / safer / more convenient than optimistic rollups.
He also speculates about the possible use of the ZK-EVM in the future. One of the development options for Ethereum is to use ZK-EVM to validate blocks in L1. This is a technically difficult option, but in the future this solution should really boost the airwaves. With the successful implementation of this model, it will be possible to run an ether node on a laptop, phone, or browser. In general, the transition to ZK-EVM in L1 seems to be a very long-term, but necessary and irreversible step.
Thus, we see that ZK-rollups in the future will surpass Optimistic rollups in everything. However, don't discount them.