Beyond the Beacon Chain: What’s Next for Eth2?

“Ben Edgington reviewed the development progress of the Ethereum beacon chain in the article and revisited Ethereum’s triple roadmap for 2021: the “merge” between Eth1 and Eth2, sharding, and light client-related specific content (announced by Vitalik in mid-November 2020). At the same time, Ben Edgington stated in the article that assuming the beacon chain continues to run smoothly, Ethereum 2.0’s task in the first few weeks of 2021 is to refine these three workstreams into specific delivery plans.”

Ben Edgington is the lead product owner of the Teku Ethereum 2.0 client at ConsenSys and a long-time chronicler of Ethereum 2.0 progress.

In 1492, Christopher Columbus thought he had reached the East Indies. In reality, he had stumbled upon an amazing new world. Sometimes, after a difficult journey, it’s best to take stock and plan anew. Seize and take advantage of new opportunities that present themselves.

This is where Ethereum 2.0 stands at the beginning of 2021. At the beginning of the year, we worked on completing the delivery of the Eth2 beacon chain and recently achieved it. This feels like the end of a long and difficult journey.

However, this is really just the beginning. We’ve come a long way, so now we can see more. As we survey the landscape ahead, we begin to realize new opportunities that are about to emerge.

For the main part of this post, I want to cover our three-fold roadmap for 2021: the “merge” between Eth1 and Eth2, sharding, and light clients. These are three separate workstreams that will be pursued in parallel. I wish us all the best.

Beacon Chain

The Beacon Chain is the foundation for the future of Ethereum. It uses Proof of Stake (PoS) instead of Proof of Work (PoW) as its governance mechanism and supports the scalability and security to sustain Ethereum's development for years to come.

The Beacon Chain went live on December 1, 2020. I call it “Proof of Stake.” Our high-value demonstration proved that it is feasible to secure a massively distributed, global, permissionless network in this way. The Beacon Chain doesn’t do much yet other than just work, and we’ll continue to discuss it, but it remains the most challenging deliverable for the Ethereum 2.0 project.

As I write, it’s been four weeks since the genesis of the Beacon Chain, and things are going great. The Beacon Chain already dwarfs all other PoS systems. Over 2 million ETH (worth $1.5 billion) has been pledged to the deposit contract. There are currently over 46,000 active validators participating, with another 20,000 waiting to join (a 3-week queue). The deposit rate for ETH2.0 validators shows no signs of slowing down. Until a few days ago, 2% of the total Ethereum supply had been locked in the deposit contract. This is a huge vote of confidence from 4,000 unique depositors, and tens of thousands more who have made deposits through the staking service.

So far, staker confidence is in good shape. Although still in its early stages, the beacon chain has been running smoothly so far, with participation rates around 99% (a key indicator of network health) and no issues or incidents.

Over the past two and a half years, hundreds of people have been involved in designing and building the Beacon Chain. It is a large-scale open community project led by the Ethereum Foundation, implemented by client development teams like myself, and supported by many different types of contributors.

It’s been an incredible journey. But this is just the first step.

What's next?

A year ago, ETH 2.0 was released with a neat, linear roadmap. Phase 0 (the beacon chain) was to be followed by Phase 1 (scalable sharding), then Phase 2 (the abstract execution engine), and finally, Eth1 would be merged into Eth2 on top of this superstructure. Then, the design of Phase 2 began to look like it would take longer than expected, and at the same time, pressure began to build to merge Eth1 into Eth2 as soon as possible. So we inserted a Phase 1.5, where Eth1 could be “lifted and shifted” directly into the Eth2 shards.

Beyond that, there’s a whole new scaling paradigm emerging that doesn’t rely on sharding at all. That’s “Rollups,” and in October, Vitalik proposed a new Ethereum roadmap centered around rollups as a path to scalability. Rollups are a so-called layer-2 technology that moves a lot of the computational and storage burden off the blockchain, and benefits from its security guarantees by just using that chain. There are a few different flavors of Rollups — zk Rollups and Optimistic Rollups — each with different tradeoffs, and the technology is nascent. But there’s a good chance that Rollups will provide a lot of the scalability that Ethereum needs before Ethereum 2.0 is fully delivered.

Stateless Ethereum (although rollups may alleviate some of Ethereum’s state bloat pressures) and promising new cryptography like Kate Commitments (pronounced “kah-tay”) also suggest exciting new directions, which also include stateless Ethereum.

With all of the above in place, our nice, neat three-phase roadmap has now evolved from Vitalik’s latest update into a spider web.

Can we really connect all these threads together? I believe that if there is any community that can do this work, it is the Ethereum community.

I recently reread Roger Lowenstein’s book Genius Failed, in which the protagonist Robert C. Merton, “suffered from a disease of total belief that made compromise impossible”. This rigidity ultimately led to the collapse of his hedge fund. Ethereum is often criticized for the opposite: a constantly rewritten roadmap; even making amends as it goes along.

But this is actually one of the driving forces of Ethereum’s success. Unlike Merton, we are a community of pragmatists who do whatever it takes to get the job done. When the facts change, we change; when opportunities arise, we seize them. We love exploring new and wild frontiers, and constantly adapt and change in the process.

Scalability

The good news is that we believe that with the completion of the Beacon Chain we have a good idea of ​​what the future holds and how 2021 will play out. Having rollups as the central hub for scalability allows us to separate tasks and attack the next phase in parallel.

So next year will be a three-pronged attack: the “merge” between Eth1 and Eth2, sharding, and light clients. In the new model, these are separate tasks and are carried out together. The order of delivery does not matter.

The merge is where we move Eth1 from Proof of Work (PoS) to Proof of Stake (PoS) nodes. The best option for achieving this right now is to build Eth1 directly into the beacon chain we already have. Eth1 will not be an execution environment as originally envisioned; it won’t even be a shard. Rather, the EVM will remain the core engine that Ethereum is built on. This will make development much simpler for developers and application providers: almost everything remains the same as it is today, we’re just turning off mining.

In our previous linear roadmap, shutting down PoW was a distant prospect, occurring after Phase 2. In the new plan, we are considering implementing a testnet in the coming weeks.

Sharding (formerly Phase 1) is now well defined and close to the point where we can start implementing it on the client side. Under the new roadmap, the approach to sharding has changed. Previously, shards were responsible for both sorting data and executing it. This introduced complications like cross-shard transactions. With the rollup-centric roadmap, shards only need to take care of sorting data. Rollups need a lot of data; the more data they have, the faster they can go.

Take the analogy of turbocharging a car. It’s funny, but it can also be used to illustrate how rollups and sharding combine to supercharge the Ethereum Virtual Machine (EVM). The EVM has proven to be powerful and flexible, but it has been lacking the oxygen it needs to accelerate: data. Rollups greatly increase the available power by compressing data (like a fuel-air mixture) and forcing it into the engine under pressure, just like a turbocharger in a car or a compressor in a jet. This can and is being done on the current Ethereum chain. When we add sharding, it’s like we’ve strapped another 64 compressors to the front of our already turbocharged engine (multi-stage turbine). Rollups and sharding, compounded, provide massive scalability.

The third, relatively minor fork is to build infrastructure for light clients. This makes the system usable for applications that don’t want to run the entire program. Light clients will allow users to prove what’s happening in Ethereum 2.0 without running an Eth2 node, which is becoming increasingly important with sharding. The whole point of sharding is that not everyone needs to run every shard.

Assuming the beacon chain continues to run smoothly, the task in the first few weeks of 2021 will be to flesh out these three workstreams into a delivery plan.

Expand or die!

The earliest reference to Ethereum 2.0 that I have managed to track down comes from Vitalik, about six and a half years ago. He begins with a somewhat prophetic statement: “We have changed our plans a lot in the last few months.” He ends by saying: “We will solve the scalability and consensus problems, or we will die trying.”

The beacon chain solves the consensus problem. And, by the end of 2021, we will know if we have solved scalability. You better believe we will work hard or die trying — it is the one constant in this ever-changing world.