Original author: Duncan
原文来源： Blocmates
原文标题：Exploring Bitcoin Layer-2s: Grift or New Paradigm?
While runes are stealing the show, Bitcoin's developers are hard at work – introducing a Frankenstein-esque monster on top of the world's most trusted blockchain. Since Bitcoin can take so many different forms, you might think that Bitcoin Layer 2 is more of a gimmick for venture capital firms than a frontier for finance.
But, dear readers, please note that Bitcoin is far more abundant than one might think.
Examples? Okay. Bitcoin is as layered as an onion.
In the current case of Bitcoin, there is L2, an emerging narrative that promises to bring Bitcoin into decentralized finance and provide people with lucrative returns. However, just like onions, there are different kinds, and how they are prepared is important. Will high-end technology attract new users, or will it only attract new holders?
What is the problem with Layer?
When we think about the second layer in the development of blockchain, we think of scalability: how do we make Bitcoin faster, better, and more powerful? Bitcoin is a bit slow, and its basic use is peer-to-peer currency transfers other than as a store of value. When we talk about layer two, we're talking about using Bitcoin in a meaningful way, like in a smart contract, to complete transactions in a reasonable amount of time, and cleanly.
This functionality already exists in the second layer of Ethereum, such as Optimism and Arbitrum batch transactions, which roll back these transactions to the main network. Developers of Bitcoin's second layer have creatively borrowed these concepts and implemented them with varying levels of complexity.
From a macro perspective, the concept is the same: Bitcoin Layer 2 aims to make Bitcoin more powerful.
How developers can prepare for the second layer of Bitcoin
Imagine cooking onions. It can enhance the taste of a dish, play a key role, or be the central point. For the second layer of Bitcoin, developers are also thinking about how to use Bitcoin. Do you want to keep it simple, or do you want to make a complete custom solution?
It turns out that the technical differences in solutions can be significant. Luckily, I've put together a menu that highlights some of the key dishes I've picked out.
Short and sweet: Citrea
In the short and sweet part, I show Citrea. Other solutions I've categorized here include Stacks, Build on Bitcoin (BOB), and SatoshiVM. They focus on the core aspects of the second layer: the scalability of the block space and the use of smart contracts. Sounds high-end, but not too crazy.
Citrea is a zero-knowledge (ZK) rollup designed to scale the Bitcoin block space. As a Rollup, it inherits the security of Bitcoin and batches transactions on Bitcoin via BitVM and verifies proof of validity.
Citrea also uses a two-way peg mechanism between Bitcoin and itself, and is compatible with the Ethereum Virtual Machine (EVM) via BitVM, which allows Bitcoin to be processed off-chain (Turing-complete) with smart contracts.
It's worth noting that Citrea is a rollup, not a side chain, just as garlic and onions are in the same family but completely different. Its goal is to scale the block space rather than transaction throughput – that is, it focuses on storing blockchain information more efficiently rather than the number of transactions processed on layer two.
In the case of Citrea, the validity proof is engraved in Bitcoin, allowing transaction batches to be easily rollup. An important difference is that these inscriptions are optimistically verified, that all transactions are valid, unless otherwise proven, and that fraud prevention is used to combat illegal transactions.
So, where does ZK apply? Well, first of all, the transaction data is not directly posted to Bitcoin itself, but only to be inscribed on it. This allows for some privacy protection for users on Citrea and other Bitcoin layer 2s that use a similar paradigm.
Second, there is a trust-minimized bridge between Citrea and Bitcoin that enables a two-way peg to Bitcoin, where funds can only be withdrawn if they pass a valid ZK proof. Citrea uses ZK-STARK, or Zero-Knowledge Succinct Non-interactive Arguments of Knowledge, to recursively validate batch proofs in a lightweight client.
This sounds a lot like "the taste of onions is controlled by thiosulfinate" – which sounds like crap to the average user. There are a lot of important technical details, but in practice, the appeal of this solution lies in its simplicity.
If we think of Citrea as another rollup, like zkSync, Arbitrum, or Optimism, it will make all the fancy-sounding ingredients easier to digest. Of course, it's not all the same, especially on a technical level; Imagine that when you use it on Ethereum, you're not handing over your bitcoins to a third party, you're using native bitcoin on Citrea: you just have to trust the open source code. It's a powerful attraction.
Tailor-made for you: Bison
When it comes to using Bitcoin natively, some teams take a different approach. In fact, there are quite a few solutions that rely on using EVMs to implement their form of DeFi. Bison Labs solves this problem with its Bison product suite, which includes Bison Network, Bison OS, and Bison Prover.
Bison comes up with his own analogy: Bison is to Bitcoin what Starknet is to Ethereum. Just like Citrea (and a few other solutions), Bitcoin network inscriptions are leveraged as a data availability layer, enhancing immutability and allowing data to be fetched more easily on-chain. They also use a zero-knowledge extensible transparent knowledge theory (or ZK-STARK for short) approach to rollups.
Bison Network has built-in components of Rollup and smart contract functionality. These components include L2 Dapp logic, sequencers and token contracts, and bridge contracts. Essentially, we can think of Bison as an advanced form of "native Bitcoin DeFi" rather than relying on EVM to handle the job.
From a culinary point of view, Bison recommends adding raw onions to dishes instead of sautéing them in olive oil every time, "because it tastes better that way."
There's a spider in your dish: Botanix
Other teams have taken a completely different approach to leveraging native Bitcoin. If you're looking for something new, then Botanix is a good choice, offering to implement proof-of-stake on its own layer 2. Yes, this is new.
Proof-of-stake (PoS) on Bitcoin is different from other PoS networks that distribute interest to holders through inflation, block rewards, or both.
In Botanix, holders lock up their bitcoins and generate fees through base transaction fees, priority transaction fees, and "down-down fees" that occur when users want to bridge to bitcoin from Botanix. Theoretically, the base reward for Botanix blocks is 0. This means that Botanix greatly benefits from higher user adoption.
Botanix protects locked bitcoins in an architectural model called "the spiderchain".
A spider chain is "a sequential series of multisig between Botanix Orchestrators" that are essentially "full nodes" of the Botanix protocol. On each block of Bitcoin, a new multisig is created between randomly selected valid Orchestrators.
Orchestrators cannot access the bitcoins in the multisig without obtaining a majority of the signatures in the random multisig, which is determined by the amount of bitcoin the orchestrators themselves stake, i.e., they must control 1/3 of the staked bitcoins. This security model means that as the network becomes more decentralized, it becomes more secure as more orchestrators join.
Now, it's important to note that Bitcoin exists "natively" on a spider chain. All bitcoins stored in the Botanix EVM section are synthetic. If user Alice bridges from Bitcoin to Botanix, her Bitcoin will be locked on the spider chain, and she will receive synthetic Bitcoin to use on the Botanix EVM.
When she wants to bridge back from Bitcoin, the synthetic Bitcoin will be destroyed and she will take back her Bitcoin from the spider chain. This is referred to as "peg-in" and "peg-out", respectively, as the supply should maintain a 1:1 ratio.
Botanix is absolutely unique – like eating a spider? I don't know. It could be disgusting, but it could also be the most delicious dish I've ever tasted. What I do know is that it's definitely cooked with onions.
Where do they overlap?
At this point, you might be wondering: Is it time to mention onions again? The answer is yes, this article is full of onion analogies.
Similarly, there are a few key components that exist in multiple Bitcoin layer 2 solutions. The main common denominator will be the use of BitVM and the use of inscriptions as a data availability layer.
Technically, BitVM is something that allows fraud proofs to be enabled on Bitcoin. Computation via BitVM is simply verified, similar to optimistic rollups, but contains elements that would normally fall under zero-knowledge rollups, such as obfuscating transaction details and bridging using trust minimization.
You'll also notice that most Layer 2 solutions take advantage of EVM compatibility to take advantage of the functionality of smart contracts and existing developer pools on Ethereum.
You may see some differences, such as whether the solution uses tokens or not. For example, Merlin Chain, Map Protocol, and SatoshiVM all have their own tokens. They are not necessarily used as gas, and there are different applications.
So, does it really matter?
Well, it depends on what kind of dish you're cooking, right? raw onions, sautéed onions, fried onions...... You know what I mean. At the heart of all of this discussion about the second layer is technology, and yes, if you're cooking, or even when you're eating something that's being cooked, that's really important. But for the average user, maybe it's not really important.
What does this mean for your portfolio? Well, it probably comes down to the user experience. If Citrea is clunky to use, although I think it's simple and straightforward, people probably won't use it. Bison and Botanix may seem overwhelming, but in real-world use they can lead to a revolutionary user experience.
But even user experience is a different science. Again, it's a question of whether people prefer raw onions, sautéed onions, fried onions or roasted onions: the market will evolve where there is demand.
Ultimately, Bitcoin's layer 2 represents an attempt at wider adoption, where the market demand is, the product goes. If people like to cook onions with spiders, then who am I to judge?
Well, admittedly, enough has been said in the article using onions as an analogy. Let me summarize it for you, without onions.
Complex technologies are simplified over time, which leads to better understanding (and therefore a better experience) for users, and sometimes you need more complex solutions. Any form of adoption is usually good for your portfolio.
Technology is great when your portfolio grows: adoption means continuous improvement of technology, leading to the emergence of new, potentially complex solutions. Typically, where there is more attention in cryptocurrency, there is more development support. In other words, your portfolio is more likely to be successful.
But we're talking about Bitcoin. People assume that these portfolios will be successful. We are interested in whether the technology will be adopted. In the second layer environment, we can see that Bitcoin is used as a currency in different environments.
However, we should ask ourselves: Is the idea of Bitcoin as a store of value or market hedging too entrenched to seriously consider this?
At first, I thought this would appeal to holders who just wanted to increase their Bitcoin holdings. The question is always who will be the first to take this step, and for successful people, their adventure will pay off handsomely. For most, it will continue to firmly maintain its current function: as a store of value and a hedge against risk.
Again, see the demand, fill the demand, and if the market needs to cook onions somehow, in certain dishes, they will have. Whether or not they are often eaten by people is another matter.
summary
Personally, I'm interested in native solutions like Bison. I think there's a market fit for a solution like Botanix, and I think the perfect intersection between the two might be somewhere.
I think there's enough market interest to justify its development, of course, but I think it's going to be a small fraction of Bitcoin's total market capitalization. After all, I think its advantage is that the Bitcoin second layer is interconnected with Bitcoin's potential relationship, although it's more interesting in terms of its relationship with Ethereum.
However, this is the real key. While Bitcoin Layer 2 is still in the incubation stage, it is working to become a truly independent ecosystem. In the meantime, we should continue to watch to see how these projects evolve and how they bring value to cryptocurrencies and blockchain.