Layer 2 scaling solutions remain a notable tool in the quest by crypto developers to solve the blockchain trilemma.
Originally coined by Ethereum co-founder Vitalik Buterin, the trilemma describes the challenges of working to build scalable, decentralized, and secure infrastructure.
Blockchains have long been forced to make trade-offs in one of these areas. However, many developers and architects believe it’s possible to build a project that hits all three targets without compromise.
Layer 2 scaling solutions like rollups have emerged as a critical tool to improve the speed and efficiency of an underline blockchain.
Layer 2 solutions run on top of sophisticated blockchains to optimize specific features and help direct transactions away from a mainnet to mitigate congestion.
Rollups carry out transaction processing off-chain after bundling (rolling up) data and then feed information to the blockchain. The idea is to reduce transaction costs by splitting them across many users.
Developers relying on rollups have two options. The first variety is known as an ‘Optimistic rollup.’ This solution assumes transactions within the rollup are valid and gives network participants a certain amount of time to dispute transactions.
John Adler wrote the first minimum viable modeling structure that described what is now known as optimistic rollups in June 2019.
According to him, their permissionless nature through merged consensus, emphasis on non-interactive fraud proofs, and sustainable scaling model by using blockchains as a data availability later make optimistic rollups a promising tool.
ZK-Rollups (Zero-Knowledge) is the other type of rollup. These tools rely on zero-knowledge proofs to determine transaction validity with only minimal information. They function similarly to Optimistic rollups while relying on the proof instead of assuming transactions are valid.
First appearing in a 1985 research paper, zero-knowledge proofs are a way to prove the validity of a certain statement while not revealing the statement. They ensure sensitive information remains confidential by relying on algorithms that use some data and return a ‘true’ or ‘false’ output.
After rolling up a bundle of transactions, the ensuing single transactions take the form of a succinct, non-interactive argument of knowledge (SNARK), or a succinct, transparent argument of knowledge (STARK). Both of these concepts are the same as a crypto transaction hash, meaning data can be represented without revealing the information itself.
As a result, ZK-SNARKs can be instantly verified when they are sent to a blockchain mainnet. Funds can be withdrawn as soon as the rollup is mined.
The speed of ZK-Rollups in moving funds to and from the mainnet has led Vitalik Buterin to predict the solution will triumph over Optimistic rollups as a more effective scaling solution. In August 2022, Buterin explained, “In more than 10 years from now or even more, I expect the Rollups to basically be all ZK.”
However, the Ethereum co-founder did admit the technology behind Optimistic rollups was more mature due to the challenges of building with existing ZK technology.
The vast potential of ZK-Rollups has led some blockchain projects to use the scaling solution as a foundation for building architecture that achieves the blockchain trilemma.
Opside describes itself in its whitepaper as a “ZK-friendly blockchain platform with unlimited scalability.” The scaling solution itself has 21 validators now, and will extend to 10000+ validators after the improved ETH2.0`s Casper PoS upgrade.
Team members note, relying on ZK-Rollup interoperability, Opside solves the blockchain trilemma through a vertical architecture that divides a system into an asset layer, execution layer, data availability later, and rollups that work together to achieve triangular architecture.
Specifically, Opside relies on decentralized chains like Ethereum and Qtum as the asset layer and establishes connections through trustless ZK-Bridges. With an EVM-compatible execution layer improving on ETH2.0’s Casper PoS system.
Opside maintains decentralization while ensuring quick confirmation time. The execution layer connects with the data availability layer to ensure low fees and reliable internal storage solutions. Opside also provides developers with ZK-Rollup SDK kits and application templates.
According to Opside team members, the “sufficient” decentralization of Ethereum and its 300,000+ post-Merge nodes ensure potential collusion remains very difficult.
Qtum’s active community, strong liquidity, and reputation as one of the first PoS public chains supporting Ethereum made the network an attractive choice. Additionally, Qutm gas fees are nearly zero and have a notable degree of decentralization (1200+ worldwide nodes) for a public chain that’s EVM-compatible.
Opside’s multi-chain, multi-rollup Web3 architecture will also act as an application layer for developers to build DEXs and NFT projects and lock assets from Ethereum and BNB Chain on Opside.
Projects like Opside continue to push towards ‘breaking’ the blockchain trilemma by building strong infrastructure to support the growing Web3 world by combining bespoke blockchain infrastructures with rollup scaling technology.