While ethereum-based layer 2 solutions have been focused on hyperscale networks, ethereum co-founder Vitalik Buterin believes that layer 3 will serve a very different purpose — providing “custom functionality.”
Buterin shares his thoughts on September 17 postal, Provides three “visions” for what the future Layer 3 will be used for.
The Ethereum co-founder said that a third layer on the blockchain only makes sense if it provides a different function than the second layer, which is mainly used to enhance scalability through zero-knowledge (ZK) aggregation techniques.
“A three-tier scaling architecture consisting of stacking the same scaling scheme on top of itself generally doesn’t work well. Rollups on top of Rollups, two-tier rollups using the same technology, of course not.”
“However, a three-tier architecture where the second and third layers have different purposes could work,” Buterin said.
One of the use cases for Layer 3 is what Buterin describes as “custom functions” — referencing a privacy-based application that would utilize ZK proofs to submit privacy-preserving transactions to Layer 2.
Another use case is “custom extensions” for specialized applications that don’t want to use the Ethereum Virtual Machine (EVM) for computation.
Buterin also said that Layer 3 can be used to scale “weak trust” through Validiums, a ZK proof technology. Buterin said this could be beneficial for “enterprise blockchain” applications, as it uses “a centralized server that runs a validating prover and regularly submits hashes to the chain.”
But Buterin added that it is unclear whether a Layer 3 structure will be more efficient than the current Layer 2 model when building custom applications on Ethereum.
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“One possible argument for the superiority of the three-tier model over the two-tier model is that the three-tier model allows the entire sub-ecosystem to exist in a single aggregate, which allows cross-domain operations within that ecosystem to happen very cheaply, without going through expensive first layer,” Buterin said.
But Buterin said that since cross-chain transactions can be performed easily and cheaply between two layer-2s that are already committed to the same chain, building layer-3 will not necessarily increase the efficiency of the network.
Buterin’s comments on possible Layer 3 use cases come as StarkWare’s newly generated recursive validity proofs appear to be putting an end to Ethereum’s scalability problems.
Declan Fox, product manager at ethereum software firm ConsenSys, recently told Cointelegraph that “with recursive aggregation and proofs, we can theoretically scale infinitely.”
These recursive proofs have been well tested in production, with StarkWare co-founder Eli-Ben Sasson telling Cointelegraph recently that its recursive proofs have accumulated as many as 600,000 NFT mints in a single transaction on Immutable X, And soon there will be 60 million transactions “with more engineering and tweaking.”