Ethereum returns to the L1 narrative, Solana Consensus accelerates

Written by: Zuo Ye

Ethereum has begun supply-side reform.

After the dream of the infinite garden shattered, Vitalik constrained the human debt of L2/Rollup, taking a more proactive stance to defend the L1 track. The Ethereum mainnet's "speeding up and reducing costs" plan is on the agenda, and the shift to Risc-V is just the beginning. How to catch up with or even surpass Solana in terms of efficiency will become the main focus moving forward.

Solana continues to expand its consumption demand scenarios.

Solana's answer is Scale or Die, steadfastly pursuing the path of becoming a larger and stronger L1. In addition to the Firedancer developed by Jump Trading entering the deployment process, at this year's Solana conference in New York, the Alpenglow consensus protocol from the Anza team took the lead, attracting everyone's attention.

The ultimate dream of Ethereum is to be a world computer, coincidentally, so is Alpenglow.

20% Security Consensus in the Era of Large-Scale Nodes

Starting from Bitcoin, the number of nodes and their dispersal are synonymous with measuring the degree of decentralization of a blockchain network. To avoid centralization, the security threshold is set at 33%, meaning no single entity should exceed this proportion.

With the boost of capital efficiency, Bitcoin mining ultimately moves towards mining pool clusters, while Ethereum becomes the main stage for Lido and CEX. Of course, this does not mean that mining pools and Lido can control the operation of the network. In the model of "maintaining the network - earning incentives / management fees," they have no motivation to act maliciously.

Image description: Blockchain node scale law, image source: @zuoyeweb3

However, measuring the health of a network must consider its scale. For example, in a small group of 3 people, a 2/3 majority is required for it to be considered effectively operating. Simply pursuing a minimum security guarantee of 1/3 is meaningless, as the remaining two can easily collude, resulting in very low costs for malicious actions and substantial gains from wrongdoing.

If it is a large-scale network of 10,000 nodes, as Etherscan indicates the current size of Ethereum nodes, there is no need to pursue a 2/3 majority vote. Outside of the incentive model, most nodes do not recognize each other, and the coordination cost for collusion between Lido and Binance is also too high.

If we reduce the number of nodes and the consensus ratio, can we "speed up and reduce costs"?

Everyone should be able to think that Alpenglow thinks so too and is ready to do just that, maintaining a scale of 1500 nodes on Solana while reducing the security consensus to 20%. This can improve node confirmation speed, allow nodes to earn more mainnet incentives, and encourage the expansion of the node scale, for example, to around 10,000.

Whether it is the effect of 1+1>2, or whether it will break through existing security mechanisms, both may occur.

However, I really like it. Solana should take the American chain, conspiracy group, and centralized route, participating in public chain competition as the opposite of Ethereum.

Magic modification of Turbine, or moving towards DPoS

The theoretical idea of Alpenglow is that in the era of large-scale nodes, a strong consensus is not required, because in a PoS mechanism, wrongdoers need to mobilize an enormous amount of capital to take control. Even at a scale of 20%, at current prices, Ethereum would need 20 billion dollars, and Solana would need 10 billion dollars.

With 10 billion dollars, why not do something good? Only a madman would try to control the blockchain, and they would face backlash from the remaining 80% of the nodes, unless it is a state action.

In practice, Alpenglow roughly divides the entire process into three parts: Rotor, Votor, and Repair (for a more detailed division and workflow, refer to its paper). To some extent, Alpenglow is a deep transformation of the Turbine mechanism, so we will briefly introduce Turbine.

Image description: Blockchain broadcasting mechanism, image source: @zuoyeweb3

Turbine is the block propagation mechanism of Solana, (Block Propagation). In simple terms, Turbine is a messenger that propagates block information to achieve consensus confirmation across all nodes.

In the early design of Ethereum, block broadcasting was based on the Gossip protocol, which in Chinese means "rumor or hearsay". Any node could act as an initial messenger, and P2P communication could occur between any nodes, ultimately achieving the effect of network-wide confirmation, much like "I have a message, I only tell you, and you must not tell anyone else"; eventually, the whole world will know.

We temporarily skip Turbine and compare it with Ripple's DPOS mechanism. Ethereum/Bitcoin has achieved the ultimate in peer-to-peer communication, but what is the cost?

It is extremely slow and expensive, which is also easy to understand. The aimless and random pairing between nodes, although it will be more robust and more resistant to censorship, will take longer. The expense comes from the cost considerations of the nodes; since the information dissemination between other nodes is slow and they need to maintain their own operation, this cost will naturally be passed on to users in the form of Gas Fee.

Extreme decentralization will inevitably lead to accompanying diseases that are both expensive and slow.

Ripple's DPOS has taken another extreme, initially setting only 21 super nodes across the entire network, an extreme centralization that completely resolves any side effects. Now the mainnet nodes have reached 179.

Turbine, on the other hand, moves towards a middle state, neither adopting Ethereum's Gossip mechanism nor heading down the wrong path of reducing the number of nodes, but instead implementing hierarchical propagation of network nodes:

1. In each cycle, nodes are divided into Leader, Relay, and more ordinary nodes, with only Leader nodes able to send block broadcast information.

2. A small number of Relay nodes continue to broadcast information to more ordinary nodes after receiving it, and the above process is called Turbine Tree, which resembles a tree with clear primary and secondary branches.

In Alpenglow, the variant of the protocol is called Rotor, which essentially refers to the orderly propagation of block messages, where any Leader or Relay node is not fixed.

Votor is a node confirmation mechanism. For example, in the Alpenglow proposal, if the first round of node voting reaches 80%, satisfying the minimum threshold of over 20%, it can be directly and quickly passed. If the first round of voting is above 60% but below 80%, a second round of voting can be initiated, and if it again exceeds 60%, it can be finally confirmed.

If it still doesn't work, then we can use the Repair mechanism, but personally, I feel that this is similar to the challenge period of Optimistic Rollup. If it comes to this point, it is highly likely that the protocol will fail, and the FDIC cannot stop the bank run on Silicon Valley Bank.

Unlike the approach of increasing bandwidth through violent stacking of hardware and software resources, Alpenglow's starting point is to reduce the process of block consensus generation.

If the data block is kept as small as possible, for example, limited to around 1500 Bytes, and the generation time is short enough, for instance, in the current testing phase, in extreme cases it can reach 100ms, which is currently 1% of 10s. (1 s = 1000 ms, though this is questionable; in real large-scale applications, the conditions won't be so ideal, but it would still be quite terrifying).

Conclusion

After MegaETH, the existing L2 basic volume reaches its endpoint. With no Solana support for SVM L2, there is an actual demand for continued expansion on the Solana mainnet. Only with mainnet TPS overwhelming all competitors can the idea of Solana as the Ethereum killer be fully realized.

Alpenglow is not only applicable to Solana; theoretically, any PoS chain, including Ethereum, can use its mechanisms. Similar to what we introduced earlier with Optimum, existing blockchain research has reached the technical edge and urgently needs more assistance from computer science and even sociological concepts.

IBM once claimed that the future of the world only needs five mainframes. If the internet built on HTTP-TCP/IP is one, BTC is one, and Ethereum is one, then there isn't much space left for Solana.

Source: Zuo Ye