MEV 已以比以太坊更微妙的形式傳播到比特幣

有幾種方法可以提前運行待處理的比特幣交易。特別是其中一個可能會導致私人記憶體池，從而導致權力的集中化

MEV, or Maximal Extractable Value, has become a hot topic in the cryptocurrency world. It refers to the ability of those who verify transactions on a blockchain to choose the order in which they are processed, allowing them to extract value from the transactions themselves. While MEV has been a common occurrence on Ethereum, it has largely been absent from Bitcoin—until now.

MEV，即最大可提取價值，已成為加密貨幣世界的熱門話題。它指的是那些在區塊鏈上驗證交易的人能夠選擇交易處理順序的能力，使他們能夠從交易本身中提取價值。雖然 MEV 在以太坊上很常見，但直到現在，它在比特幣中基本上還沒有出現。

In this article, we will explore the different ways in which MEV can manifest on Bitcoin, ranging from front-running NFT trades on marketplaces to the mining of empty blocks and the use of out-of-band payments. We will also touch on the potential implications of these practices, such as the slippery slope towards private mempools and the centralization of authority on the blockchain.

在本文中，我們將探討 MEV 在比特幣上體現的不同方式，從市場上的搶先交易 NFT 交易到空塊的挖礦和帶外支付的使用。我們還將討論這些做法的潛在影響，例如私人記憶體池的滑坡和區塊鏈上的權力集中。

MEV on Ethereum: A quick refresher

以太坊上的 MEV：快速回顧

As a quick refresher, MEV on Ethereum is possible due to the way transactions are processed on the network. When a user submits a transaction, it is placed in a mempool, which is a collection of pending transactions waiting to be included in a block and processed by a validator. The validators, who are selected based on their stake in the network, then choose which transactions to include in each block.

快速回顧一下，由於網路上處理交易的方式，以太坊上的 MEV 是可能的。當使用者提交交易時，它會被放置在記憶體池中，記憶體池是等待包含在區塊中並由驗證器處理的待處理交易的集合。根據他們在網路中的權益選擇的驗證者然後選擇要包含在每個區塊中的交易。

Since the validators are able to see all of the transactions in the mempool, they can front-run them by submitting their own transactions first. This allows them to extract value from the original transactions, such as by purchasing an NFT at a lower price before the intended buyer's transaction is processed.

由於驗證者能夠看到記憶體池中的所有交易，因此他們可以透過先提交自己的交易來預先運行它們。這使他們能夠從原始交易中提取價值，例如在處理預期買家的交易之前以較低的價格購買 NFT。

While front-running is one of the most common types of MEV on Ethereum, there are a number of other ways in which validators can extract value from transactions. These include sandwich trades, where a validator places two transactions around the original transaction to extract value from both sides, and transaction reordering, where a validator changes the order of transactions in a block to benefit themselves.

雖然搶先交易是以太坊上最常見的 MEV 類型之一，但驗證器還可以透過許多其他方式從交易中提取價值。其中包括三明治交易，驗證者在原始交易周圍放置兩筆交易以從雙方提取價值，以及交易重新排序，其中驗證者改變區塊中的交易順序以使自己受益。

MEV on Bitcoin: More subtle, but still present

比特幣上的 MEV：更微妙，但仍然存在

In contrast to Ethereum, where MEV is a highly visible and well-defined phenomenon, MEV on Bitcoin is more subtle and can manifest in a variety of ways. Some of the most common include:

與以太坊相比，MEV 是一種高度可見且定義明確的現象，而比特幣上的 MEV 則更加微妙，可以透過多種方式體現。一些最常見的包括：

Front-running NFT trades on marketplaces: One way in which MEV can occur on Bitcoin is through the front-running of NFT trades on marketplaces such as Magic Eden. When a seller lists an NFT for sale on these marketplaces, they create a Partially Signed Bitcoin Transaction (PSBT). The buyer then completes the transaction by adding their signature and paying the fee.

市場上搶先交易的 NFT 交易：MEV 在比特幣上發生的一種方式是透過在 Magic Eden 等市場上搶先交易的 NFT 交易。當賣家在這些市場上出售 NFT 時，他們會創建部分簽署的比特幣交易（PSBT）。然後，買方透過添加簽名並支付費用來完成交易。

However, if an NFT trader sees the transaction in the mempool, they can snipe it by broadcasting their own transaction that replaces the original buyer's payment and address with their own. To do so, they broadcast a Replace-By-Fee (RBF) transaction with a higher fee to ensure that their transaction is confirmed before the original one.

然而，如果 NFT 交易者在內存池中看到該交易，他們可以通過廣播自己的交易來狙擊它，該交易用自己的交易替換了原始買家的付款和地址。為此，他們廣播了費用更高的替換費用（RBF）交易，以確保他們的交易在原始交易之前得到確認。

This allows them to purchase the NFT at the price set by the seller, while the original buyer is left out in the cold.

這使得他們能夠按照賣家設定的價格購買 NFT，而原始買家則被冷落。

Mining of empty blocks: Another way in which MEV can manifest on Bitcoin is through the mining of empty blocks. Periodically, a bitcoin block is mined with nothing in it. The block is useless to anyone save the miner who won the block, as no transactions which are waiting to be confirmed are verified except for the coinbase (small "c," not the company) transaction which rewards the miner with the block reward.

空塊挖礦：MEV 在比特幣上體現的另一種方式是透過空塊挖掘。比特幣區塊會定期被開採，但裡面卻什麼都沒有。除了贏得該區塊的礦工之外，該區塊對於任何人來說都是無用的，因為除了用區塊獎勵獎勵礦工的coinbase（小“c”，不是公司）交易之外，沒有任何等待確認的交易得到驗證。

There’s a technical reason this happens, and really it’s an accident that empty blocks even occur, but it’s hard to argue that this is a) not MEV and b) good for Bitcoin (although it is also hard to argue that it’s bad).

發生這種情況有一個技術原因，事實上，甚至出現空塊也是一個意外，但很難說這是 a) 不是 MEV，b) 對比特幣有利（儘管也很難說這是壞事）。

Cartel behavior among miners: As we all know, Bitcoin is mined by powerful computers that solve complex mathematical puzzles. The miner who solves the puzzle first gets to add the next batch of transactions to the blockchain and collect the associated fees.

礦工之間的卡特爾行為：眾所周知，比特幣是由能夠解決複雜數學難題的強大電腦開採的。首先解決難題的礦工可以將下一批交易添加到區塊鏈並收取相關費用。

In the early days of Bitcoin, individual miners competed fiercely for this prize. However, as the network has grown more competitive and the puzzles have become harder to solve, many miners have joined forces and created mining pools. These pools combine the computational power of all their members and then split the rewards among them, regardless of who actually solved the puzzle.

在比特幣的早期，個體礦工為了這個獎項展開了激烈的競爭。然而，隨著網路競爭越來越激烈，謎題也越來越難解決，許多礦工聯合起來創建了礦池。這些池結合了所有成員的計算能力，然後在他們之間分配獎勵，無論誰真正解決了難題。

While mining pools can help to stabilize the income of individual miners and make the process of mining more efficient, they can also introduce new opportunities for MEV. For example, if a mining pool were to gain control of a majority of the network hashrate, it could use this power to extract value from transactions by prioritizing certain transactions over others.

雖然礦池可以幫助穩定個體礦工的收入並使挖礦過程更加高效，但它們也可以為 MEV 帶來新的機會。例如，如果礦池要獲得大部分網路哈希率的控制權，它可以利用這種權力透過優先處理某些交易而不是其他交易來從交易中提取價值。

Out-of-band payments to miners: Finally, another way in which MEV can occur on Bitcoin is through out-of-band payments to miners. This practice involves paying miners (either off-chain, or in a separate and seemingly unrelated bitcoin transfer) to accept transactions which are considered non-standard.

向礦工進行帶外支付：最後，MEV 在比特幣上發生的另一種方式是透過向礦工進行帶外支付。這種做法涉及向礦工付費（無論是鏈下的，還是單獨且看似無關的比特幣轉帳），以接受被認為是非標準的交易。