Vitalik Compares the L2 and Ethereum Sharding Visions

Today, Ethereum founder Vitalik Buterin released an analysis of Layer 2s (L2s) and base layer execution sharding in scaling Ethereum, highlighting the key similarities and differences in these approaches.

What's the context?

In his new post, Buterin explored the parallels between L2s and sharding, noting how these approaches similarly aim to handle a large volume of transactions efficiently.

He emphasized that the endgame for both these methods is relying on ZK-SNARKs for computation verification and Data Availability Sampling (DAS) for data verification. Despite these similarities, he went on to explain how there are distinct differences that persist.

Summarizing the tradeoffs

• As Vitalik noted, L2s provide a variety of execution environments, allowing for different virtual machines and architectures, such as Arbitrum Stylus (WASM-based), Fuel (UTXO-based), and Aztec (ZK-SNARK-based privacy).
• This diversity enables specialized implementations that wouldn’t be feasible with the single, monolithic Ethereum Virtual Machine (EVM) that sharding would be limited by.
• Additionally, the Ethereum L1 offers more robust security guarantees at a higher cost, while L2s offer a spectrum of security and cost tradeoffs, making them suitable for non-financial applications like social media and gaming.
• L2s can also provide faster transaction times using preconfirmation mechanisms, a feature that would complicate L1 if implemented directly. On the flip side, L2 cross-chain capabilities still need work.
• Culturally speaking, L2s also foster independent sub-ecosystems within Ethereum to an extent that shards likely wouldn't. This encourages innovation and specialization while benefiting from Ethereum's shared security and network effects.
• In the same vein, rollups allow developers to experiment with new ideas without needing consensus from Ethereum core developers, reducing the political overhead associated with L1 changes.

Vitalik's conclusion

Buterin wrapped up by reiterating that while L2s and sharding have their idiosyncracies and are often seen as distinct scaling strategies, they are fundamentally similar in their general technical approaches.

The main difference, he noted, lies in who builds and maintains these components and the level of autonomy they possess. He concluded by emphasizing the need for addressing the coordination challenges of an L2-centric approach to fully realize its potential.

Bankless take:

Some people in the Ethereum community still long for the original sharding vision, though as Vitalik's new post demonstrates, Ethereum has taken an approach via L2s that, in effect, is sharding–it's just arrived along a different path than was initially planned. While pure sharding has its pros, the flexibility possible with rollups is a big leg up and highlights how Ethereum is now well-suited for development efforts of all stripes.