Layer 2 (L2) is a standard time period amongst crypto natives, however the idea will be complicated for many individuals, particularly those that have simply joined the trade.
It’s a generic title used to explain options constructed on a base community, popularly referred to as layer 1 (L1) or the principle community (Mainnet). Which means that L2 can’t exist with out the bottom layer, which makes it important to first have a fundamental data of L1 earlier than studying about L2.
Layer 1 Defined
So what’s layer 1? It’s the base community and underlying infrastructure of a blockchain platform. The principle community is chargeable for validating and finalizing all on-chain transactions with out relying on one other community. This implies the bottom layer defines the rule of the ecosystem. L1 protocols even have native tokens used for transaction charges or fuel charges.
Each base community has its personal mechanism for nodes to succeed in a consensus, similar to proof-of-work (PoW) and proof-of-stake (PoS). Nevertheless, there’s a quite common idea within the trade generally known as the blockchain trilemma, the place a community can obtain two of the three major targets – safety, scalability, and decentralization – however not all three collectively. This was popularized by Ethereum’s co-founder, Vitalik Buterin.
Layer 1 blockchains similar to Bitcoin and Ethereum give attention to decentralization and safety whereas sacrificing scalability – the power to deal with many transactions. That is the place layer 2 protocols are available. Builders construct L2 options on L1 to resolve scalability points.
What’s Layer 2 and How Does it Work?
Layer 2 protocols are options constructed on high of a base community to assist scale transactions and information. L2 serves as an extension or a secondary framework for his or her respective major networks.
So how does it work? Layer 2 networks course of transactions in massive bundles on their very own earlier than submitting proof of the transactions to the bottom layer. This course of is often known as “off-chain” scaling, and it takes an enormous load off the bottom community.
L1 focuses on safety, decentralization, and information availability, whereas L2 handles scalability. This makes all the blockchain ecosystem extra scalable because the base community is much less congested. So mainly, it’s teamwork.
Layer 2 Vs Sidechains
Layer 2 options and sidechains are designed to assist their major networks scale sooner. Whereas L2 is constructed on high of its base chain, a sidechain runs in parallel as an unbiased EVM-compatible chain interacting with the first community by way of bridges.
The principle distinction between layer 2 protocols and sidechains is that L2 inherits the safety of the mainnet, whereas sidechains could undertake their very own safety or that of different protocols. Thus, sidechains are technically not thought-about L2 options.
Curiously, tasks similar to Polygon Community mix a number of L2 and sidechain applied sciences to make transactions sooner and cheaper.
Advantages of Layer 2 Networks
Scalability: Scalability offers with transaction throughput and pace. In different phrases, it ensures larger transactions are processed per second with sooner completion. Many base networks favor to sacrifice scalability for decentralization or safety, which ends up in congestion throughout excessive community utilization.
Layer 2 networks resolve this drawback as they assist blockchain ecosystems to scale with out compromising safety or decentralization.
Decrease charges: As talked about earlier, L2 bundles a number of transactions and submits them to the mainnet as a single transaction. This helps to cut back transaction charges, making the bottom layer cheaper and sooner.
Preserve Safety: Safety and decentralization are the core focus of layer 1 networks. Since layer 2 chains are constructed on high, customers can profit from the safety of the first blockchain.
Drawbacks of Layer 2 Networks
Liquidity Discount: Liquidity is a vital facet of the crypto market. Layer 2 networks can scale back the liquidity of their main blockchains, which should be strong and liquid always.
Could Require A number of Accounts: When a number of L2 options are constructed on high of a community, the L1 and its completely different purposes would require extra bridges to make sure clean communication between the 2 layers. This implies end-users will typically must create a number of accounts to switch funds between the completely different protocols. The method will be daunting, particularly since customers have to trace the motion of their property always.
Safety Issues: Whereas it is a matter of implementation, the previous 12 months noticed a number of bridging options getting hacked, resulting in a whole bunch of tens of millions price of cryptocurrency being compromised.
Kinds of Layer 2 Options
There are various kinds of layer 2 applied sciences that present scaling options for blockchain networks, thus permitting many individuals to make use of layer 1 protocols similar to Bitcoin and Ethereum for day by day transactions.
The most well-liked layer 2 scaling options embrace Rollups, centered on Ethereum, whereas the Bitcoin Lightning Community works to extend the scalability of Bitcoin.
Rollups
Rollup is a well-liked layer 2 system that scales the Ethereum mainnet and different blockchains. So how does it work?
Rollups are common sensible contracts that relay information between layer 1 and layer 2. They assist the blockchain scale by transferring bulk transactions and information from the bottom layer onto the L2. As soon as the transactions have been processed on layer 2, rollups return the transaction information to the mainnet for storage.
Along with scaling the bottom layer, rollups are designed to considerably scale back fuel charges by grouping or “rolling up” a whole bunch of transactions right into a single transaction earlier than transferring it to the bottom layer. The transaction payment is then shared by everybody within the group, making it cheaper for every person. This permits rollup options to cut back transaction charges by as much as 100x in comparison with the bottom layer.
Moreover, rollups are constructed on high of the L1, which permits them to derive their safety from the first blockchain.
That mentioned, there are two sorts of rollups – zero-knowledge (ZK) and Optimistic. The key distinction is how they switch the transaction information again to the mainnet.
Zero-Information Rollups
Zero-knowledge rollups or ZK rollups take a number of transactions from the bottom layer and course of them off-chain, after which push the transactions in batches again to the mainnet by way of an on-chain rollup sensible contract.
Throughout this course of, ZK rollups generate a cryptographic proof referred to as SNARK (Succinct Non-Interactive Argument of Information) or STARKs (scalable clear argument of information) despatched to the L1 to show the correctness of the transactions. This permits verifiers to know that they’ve the identical data with out revealing what they know, therefore the title, zero-knowledge.
Zero-knowledge rollup chains can produce a block inside a minute whereas processing as much as 2,000 transactions per second. This drastically reduces the fee and time required for processing transactions on the blockchain.
Examples of L2 protocols leveraging Optimistic rollups
- Loopring
- zkSync
- ZKSpace
- Aztec
Optimistic Rollups
Like ZK rollups, Optimistic rollups course of massive volumes of transactions off-chain earlier than posting the info again to the bottom layer.
The principle distinction, nevertheless, is that Optimistic rollups don’t generate cryptographic proof to show the authenticity of the transactions. As an alternative, they assume that the transactions are legitimate till confirmed in any other case.
Optimistic rollups supply a time window referred to as the problem interval that permits anybody to problem the outcomes of submitted state information. This may be achieved by computing a “fraud-proof.” If the fraud-proof is confirmed and accepted, the roll-up chain re-executes the false transaction and updates the state information.
Total, Optimistic rollups supply much less throughput when in comparison with ZK rollups and Plasma (defined under).
Examples of L2 protocols leveraging Optimistic rollups
- Arbitrum One
- Optimism
- Boba Community
Plasma
Plasma is an Ethereum layer 2 scaling framework created by Vitalik Buterin and Joseph Poon, the writer of the Bitcoin Lightning Community (defined under).
Not like rollups, the Plasma construction combines sensible contracts and Merkle bushes to create an infinite variety of sidechains referred to as “baby chains” on high of the Ethereum major chain. Though these baby chains are small copies of the mainnet, they course of transactions off-chain with their very own consensus mechanism for validating blocks. Taking the transactions off the principle chain helps scale back congestion and enhance scalability.
Like Optimistic rollups, every baby chain within the Plasma construction makes use of a proof of fraud system for safety, with a time interval for anybody to problem the transaction’s validity.
It’s price noting that, not like different sidechains, Plasma inherits the safety of Ethereum. It is because the “root” of every chain block within the Plasma construction is revealed on the mainnet.
Polygon and OMG are examples of protocols leveraging the facility of Plasma on the Ethereum community.
It’s price noting, although, that Plasma Group (the Ethereum analysis group) ceased working and donated the remaining of its funds to Gitcoin for use on optimistic rollups.
Bitcoin Lightning Community
The Lightning Community (LN) is Bitcoin’s hottest layer 2 scaling resolution. It was proposed in 2016 to resolve the scalability points on the Bitcoin community by processing transaction bundles at a lightning-fast pace.
Like different L2 scaling options mentioned above, LN takes a number of transactions from the mainnet and processes them off-chain by way of micropayment channels earlier than returning the transaction information.
Though the Lightning Community was initially designed to scale Bitcoin, cryptocurrencies similar to Litecoin and Dogecoin have additionally built-in the answer.
Ultimate Ideas
In abstract, layer 2 protocols are scaling options constructed on high of a main blockchain to assist enhance transaction pace and reduce prices. L2 chains are quick changing into the reply to the scalability points present in main blockchains similar to Bitcoin and Ethereum.
