It’s been two years since the Ethereum Merge was finalised, marking the moment when the network officially moved from being a proof-of-work (PoW) chain to a proof-of-stake (PoS) one. 

While that was a significant milestone in Ethereum’s history, the network’s roadmap towards ‘Etheruem 2.0’ was only 55% complete. Ethereum cofounder Vitalik Buterin laid out plans for further upgrades through phases which he referred to as “surge”, “scourge”, “verge”, “purge” and “splurge.”

The “verge” phase is meant to include stateless clients and verkle trees — mathematical proofs that will tackle the issue of high storage requirements for running a full node on the blockchain.

“Today, the Verge represents a much larger vision focused on enabling maximally resource-efficient verification of the Ethereum chain, which includes not just stateless validation technology, but also verifying all Ethereum execution with SNARKs,” said Buterin in an Oct. 23 blog post. 

SNARKs allow one party to prove to another that they possess certain information without revealing the information itself. They also allow complex computations to be verified quickly on-chain.

Longer term, Buterin sees one of the key goals for Etheruem during the verge phase as making it possible for the chain to be fully verifiable on both the consensus and execution level on a smart watch.

“Today, running a node is possible on a consumer laptop, but doing so is difficult,” said Buterin.

“The Verge is about changing this, and making fully-verifying the chain so computationally affordable that every mobile wallet, browser wallet, and even smart watch is doing it by default.”

The community of developers will still need to debate what the best way to go about achieving stateless verification is, and whether that still involves verkle trees or STARKS (similar to SNARKs, but addressing some of that proof system’s limitations).

“Realistically, it will take years before we have a validity proof of the Ethereum consensus,” said Buterin, adding that in the long term, “STARK-friendliness needs to be a primary concern in long-term redesigns of the Ethereum proof of stake consensus.”