Ahmed Ali First-layer (L1) and second-layer (L2) blockchain solutions offer divergent methodologies for enhancing the scalability of distributed ledger networks. Developers working on first-layer blockchains are primarily concerned with optimizing the core protocol, whereas second-layer engineers shift transactions to off-chain channels to ensure quicker and more cost-effective processing.
What Constitutes First-Layer Blockchains?
First-layer, commonly known as L1, designates foundational blockchain protocols like Bitcoin and Ethereum. Operating on decentralized ledgers that are secured either through proof-of-work (PoW) or proof-of-stake (PoS) mechanisms, networks like Bitcoin and Ethereum boast high levels of security. Yet, these networks confront challenges such as delayed transaction times and elevated transaction fees, particularly during periods of heavy usage.
Various developers within the L1 ecosystem are directing their efforts towards enhancing scalability at the first layer. Strategies under consideration include enlarging block sizes, sharding, and the transition to a proof-of-stake consensus mechanism. Significant upgrades to the first layer entail extensive coordination among node operators and are often time-consuming to deploy. Numerous blockchains are looking to second-layer protocols as either interim or enduring solutions to these challenges.
The Anatomy of Second-Layer Blockchains
Second-layer, or L2, solutions capitalize on the robust security of an existing L1 blockchain, facilitating more rapid and economical off-chain transactions. The processed data is typically consolidated and reconciled on the first layer, although there are exceptions to this rule.
Key Second-Layer Innovations:
Lightning Network for Bitcoin
The Lightning Network serves as Bitcoin’s second-layer scalability solution, aimed at delivering expedited and cost-efficient transactions. Operating atop Bitcoin’s foundational layer, it enables instantaneous payments by sidestepping the necessity for block validations.
In the Lightning Network, transactions are conducted off-chain through payment channels established between parties. The Bitcoin blockchain only records the initiation and termination of these channels, allowing for multiple transactions within them, which reduces both congestion and fees on the first layer.
However, the Lightning Network has garnered criticism due to its common utilization of custodial wallets, necessitating users to trust third-party service providers with their assets. Additionally, there is an inherent risk of irrecoverable loss of funds should nodes fail to maintain adequate backups.
Loopring and ZK-Rollups for Ethereum
Loopring employs zero-knowledge rollups (ZK-rollups) to bundle multiple off-chain transactions and produce a cryptographic proof affirming their legitimacy. This proof is subsequently submitted to the first layer (Ethereum), thereby obviating the need to process each individual transaction on-chain.
Polygon ZKEVM also utilizes ZK-rollup technology to facilitate high-volume Ethereum transactions at reduced costs.
