Buterin wants faster Ethereum block finalization but there are 3 challenges

Ethereum co-founder Vitalik Buterin has noted that while the shift from Proof of Work (PoW) to Proof of Stake (PoS) was a major event, there are areas that still need improvement. In a recent blog post, he underlined the importance of making staking more accessible and speeding up block finalization.

The upgrades aim to enhance decentralization and improve user experience but Buterin warns they also come with trade-offs in terms of network complexity and security.

Buterin wants to promote solo staking

Two years after Ethereum’s transition from PoW to PoS, co-founder Vitalik Buterin has pointed out areas that still need work. In a recent blog, he explained that The Merge was a huge milestone that improved network stability and performance. Buterin talks about planned improvements under technical upgrades that will make block finalization faster and lower the amount of ETH needed to stake.

The two concepts have been discussed in the Ethereum community to promote solo staking. Solo staking is known to improve decentralization as individuals can participate in staking without many barriers. Cryptopolitan reported on Buterin’s proposal to lower ETH staking from 32 ETH to 1 ETH. It can only be achieved by the technical upgrades but with a trade-off. Buterin underlines that block finalization time is currently around 15 minutes along with a high staking requirement. But, Buterin states, “The goals of faster finality and more democratized staking both conflict with the goal of minimizing overhead.”

This means that Ethereum has to balance the number of validators while keeping the node requirements low and reducing the finality time. The conflict is that more validators lead to more decentralization but it can also lead to longer verification times unless there are powerful nodes. The Ethereum co-founder reiterates that the future goal is single-slot finality i.e. finalizing blocks in one slot in around 12 seconds.

He explains that other consensus algorithms, like Tendermint, have achieved fast finality. However, Ethereum’s need for inactivity leaks brings unique challenges. Inactivity leaks on the Ethereum network keep it running even if more than 1/3 of the validators go offline. But Buterin proposes 3 options when Ethereum can achieve single-slot finality work with many validators without high node overheads.

The trade-off of Ethereum’s complexity and security

Buterin proposes Brute force for better signature aggregation as the first option. He explains that by using techniques like ZK-SNARKs, the network could handle signatures from millions of validators without slowing down.

Option 2 is orbit committees where a sub-committee instead of all validators finalizes the blocks. Buterin suggests that the idea balances efficiency with security. Validators would rotate slowly between committees to maintain security.

The third proposal is two-tiered staking: Buterin envisions two groups of stakers—one group with high deposits and another with lower deposits. He says that under this option, only the higher-tier stakers would handle economic finality. But lower-tier stakers could have other rights like delegating their stake to higher-tier stakers.

While incorporating these three options Buterin sees 4 possible paths for Ethereum. First leaves Ethereum as is while leaving the network’s security and decentralization with no improvements. Second is Orbit SSF which will adjust the assumptions around economic finality. Third is the tech-heavy Brute-force SSF route to handle millions of validator signatures quickly. Fourth is two-tiered staking which creates two staking classes but creates risks of centralization.

The Ethereum co-founder also looks at a hybrid future that could incorporate a mix of these strategies. Considering single-slot finality reduces the risks of certain MEV attacks, Buterin says that the goal is to find a protocol that’s easy to implement on Ethereum.

For adding complex features like features like Single Secret Leader Election (SSLE), Buterin believes that one can wait until Ethereum adopts ZKPs. Hoping that Zero-Knowledge Proofs (ZKPs) can reduce the complexity of adding more features.

He also proposes out-of-protocol fixes that do not need SSLE changes. This option would only fix vulnerabilities at the network layer. However, Buterin also says that SSLE would benefit protocol-related blocks despite not needing it for regular transactions.

Amid the changes, Buterin also points to over-reliance on the social layer during a 51% attack. Buterin says that the goal is to automate part of the recovery process as full automation is “impossible.” The developer also touches upon increasing the quorum threshold to 80% as currently, a block is final if 67% of stakers approve it. Buterin’s changes could give more importance to solo stakers.