缺失的操作码：为什么比特币 L2 需要 OP_CAT 才能成熟

比特币 L2 是人们谈论的话题，但它们的承诺尚未实现。比特币的建设者还在等什么？

Bitcoin Layer 2 (L2) protocols have been generating a lot of buzz recently, but their full potential has yet to be realized. Now, an important proposal could accelerate the development of the Bitcoin L2 landscape: the reintroduction of OP_CAT.

比特币第 2 层 (L2) 协议最近引起了广泛关注，但其全部潜力尚未实现。现在，一个重要的提议可以加速比特币 L2 格局的发展：重新引入 OP_CAT。

This opcode, which was disabled early on in Bitcoin's history, could unlock new possibilities and pave the way for more advanced and trustless Bitcoin L2 solutions.

这个在比特币历史早期就被禁用的操作码可以释放新的可能性，并为更先进和无需信任的比特币 L2 解决方案铺平道路。

Let's dive into why this opcode is so crucial for BTC 👇

让我们深入探讨一下为什么这个操作码对 BTC 如此重要👇

What is OP_CAT?

什么是OP_CAT？

OP_CAT, or "Operation Concatenate," is an opcode in Bitcoin's scripting language that enables the concatenation of two data elements.

OP_CAT，或“连接操作”，是比特币脚本语言中的一个操作码，可以连接两个数据元素。

Initially proposed by Satoshi Nakamoto, OP_CAT was disabled in 2010 due to security concerns related to its original implementation, specifically potential denial-of-service (DoS) attacks caused by unbounded memory usage.

OP_CAT 最初由中本聪 (Satoshi Nakamoto) 提出，由于与其原始实现相关的安全问题，特别是无限制内存使用导致的潜在拒绝服务 (DoS) 攻击，OP_CAT 于 2010 年被禁用。

However, the introduction of the Taproot upgrade in 2021 has addressed these original concerns. Taproot now enforces a maximum stack element size of 520 bytes, addressing the memory usage issue that led to OP_CAT's deactivation.

然而，2021 年 Taproot 升级的推出解决了这些最初的担忧。 Taproot 现在强制最大堆栈元素大小为 520 字节，解决了导致 OP_CAT 停用的内存使用问题。

With this improvement and the renewed interest in Bitcoin development, thanks to Ordinals and Runes, a movement to reintroduce OP_CAT to enhance Bitcoin's scripting capabilities is gaining momentum, aiming to enable more complex transaction capabilities.

随着这一改进以及人们对比特币开发的新兴趣，得益于 Ordinals 和 Runes，重新引入 OP_CAT 以增强比特币脚本功能的运动正在获得动力，旨在实现更复杂的交易功能。

Are Covenants and Smart Contracts Different?

契约和智能合约有不同吗？

One reason why OP_CAT is so interesting is that it can enable covenants, or spending conditions, on Bitcoin. Covenants and smart contracts are both mechanisms for controlling the flow of funds in a blockchain network, but they operate in distinct ways.

OP_CAT 如此有趣的原因之一是它可以在比特币上启用契约或支出条件。契约和智能合约都是控制区块链网络中资金流动的机制，但它们的运作方式不同。

Covenants

契约

Smart Contracts

智能合约

Why Does OP_CAT Matter for Bitcoin L2s?

为什么 OP_CAT 对于比特币 L2 很重要？

OP_CAT would be crucial for advancing Bitcoin L2 solutions because it enhances the scripting capabilities needed for more complex and trustless Bitcoin infrastructure.

OP_CAT 对于推进比特币 L2 解决方案至关重要，因为它增强了更复杂和无需信任的比特币基础设施所需的脚本功能。

Firstly, OP_CAT enables covenants, allowing for the construction of more advanced scripts. This is essential for creating the complex transaction conditions and functionalities required for L2 solutions.

首先，OP_CAT 支持契约，允许构建更高级的脚本。这对于创建 L2 解决方案所需的复杂交易条件和功能至关重要。

Moreover, with OP_CAT, users can unilaterally withdraw their funds from shared UTXOs, ensuring they can reclaim their assets without needing consent from other parties. This is also vital for trustless L2 protocols.

此外，通过OP_CAT，用户可以单方面从共享UTXO中提取资金，确保他们无需其他方同意即可收回资产。这对于无需信任的 L2 协议也至关重要。

For example, CatVM, proposed by Taproot Wizards, would use OP_CAT to build a mechanism for locking and withdrawing funds in an L2 environment. It leverages OP_CAT's ability to concatenate data and verify Merkle tree branches, facilitating secure withdrawal processes.

例如，Taproot Wizards 提出的 CatVM 将使用 OP_CAT 构建在 L2 环境中锁定和提取资金的机制。它利用 OP_CAT 连接数据和验证 Merkle 树分支的能力，促进安全提款过程。

OP_CAT also enables the creation of fraud proofs a la optimistic rollups to prevent double-spending and ensure the integrity of offchain transactions, another promising path for Bitcoin L2s.

OP_CAT 还可以通过乐观汇总创建欺诈证明，以防止双重支出并确保链下交易的完整性，这是比特币 L2 的另一条有前途的途径。

Will OP_CAT be Activated?

OP_CAT 会被激活吗？

The reactivation of OP_CAT is currently being discussed in the Bitcoin community. While there is strong support for its potential benefits, the conservative approach to protocol changes in Bitcoin means that thorough testing and consensus-building are necessary steps before activation.

目前比特币社区正在讨论重新激活 OP_CAT。虽然其潜在好处得到了强有力的支持，但比特币协议变更的保守方法意味着彻底的测试和建立共识是激活之前的必要步骤。

However, if the proposal to re-enable OP_CAT is approved, it could be implemented within six months to a year, depending on the community's consensus and the results of the testing phase.

不过，如果重新启用 OP_CAT 的提案获得批准，可能会在六个月到一年内实施，具体取决于社区的共识和测试阶段的结果。

Furthermore, if OP_CAT is activated, projects like StarkWare are ready to begin development on top of it. StarkWare plans to use OP_CAT to bring zero-knowledge (ZK) scaling to Bitcoin, enabling advanced financial instruments and applications on the network.

此外，如果 OP_CAT 被激活，像 StarkWare 这样的项目就可以在其之上开始开发。 StarkWare 计划使用 OP_CAT 为比特币带来零知识 (ZK) 扩展，从而在网络上实现先进的金融工具和应用程序。

StarkWare’s involvement here highlights the broader ecosystem's readiness to capitalize on the enhanced capabilities that OP_CAT would introduce.

StarkWare 的参与凸显了更广泛的生态系统已准备好利用 OP_CAT 将引入的增强功能。

As the community continues to explore and test the possibilities around this proposal, the future of Bitcoin L2s looks promising and ripe with potential. At this point, reactivating OP_CAT seems like a matter of when not if!

随着社区继续探索和测试围绕该提案的可能性，比特币 L2 的未来看起来充满希望并且潜力十足。此时，重新激活 OP_CAT 似乎只是何时而不是是否的问题！