三明治攻擊：加密交易者的詳細指南

三明治攻擊是一種市場操縱形式，它針對用戶進行分散交流，從而利用價格變動來從受害者的貿易中獲利。

A sandwich attack is a type of front-running exploit in which an attacker places two orders around a victim’s trade in a way that profits from price slippage.

三明治攻擊是一種前進的漏洞，其中攻擊者在受害者的貿易周圍下達了兩個訂單，從而從價格滑倒中獲利。

In a typical sandwich attack, a malicious actor watches the transaction mempool for large trades that might affect the price of a cryptocurrency. 

在典型的三明治襲擊中，惡意演員觀看了可能影響加密貨幣價格的大型交易的交易Mempool。

After being identified, the attacker executes a “back-running trade” by placing a “sell” order immediately following the victim’s trade and a “buy” order just before it.

在被確定後，攻擊者通過在受害者交易後立即下達“賣出”訂單，並在其之前下達“買入”訂單，從而執行“後交易”。

The victim’s trade contributes to the manipulated price, which is intentionally inflated or deflated to their benefit. The attacker makes money by selling their coins once the victim’s transaction is completed.

受害人的貿易有助於操縱價格，該價格有意膨脹或放氣。受害者的交易完成後，攻擊者通過出售硬幣來賺錢。

Why sandwich attacks matter for crypto traders

為什麼三明治攻擊對加密交易者很重要

Sandwich attacks matter significantly for crypto traders, especially beginners, due to their impact on maximal extractable value (MEV).

三明治攻擊對加密貨幣交易者，尤其是初學者而言至關重要，因為它們對最大可提取價值（MEV）的影響。

MEV refers to the additional value that can be extracted from block production beyond standard block rewards. In essence, it allows miners or validators to strategically order transactions within a block to maximize their own profits.

MEV是指超出標準塊獎勵以外的塊生產中可以提取的其他值。從本質上講，它允許礦工或驗證者在塊內策略性地訂購交易，以最大化自己的利潤。

Sandwich attacks are a prime example of MEV exploitation. By manipulating transaction order, attackers capitalize on the public nature of the blockchain to front-run and back-run trades, profiting from the price slippage they induce.

三明治攻擊是MEV開發的一個典型例子。通過操縱交易訂單，攻擊者利用區塊鏈的公共性質到前進和後運行的交易，從他們誘發的價格滑倒中獲利。

Here’s how these attacks impact traders:

這些攻擊是如何影響交易者的：

Due to these concerns, the crypto community actively explores solutions to mitigate the negative impacts of MEV, such as:

由於這些擔憂，加密貨幣社區積極探索解決方案，以減輕MEV的負面影響，例如：

Did you know? Maximal extractable value was once called miner extractable value. First introduced in the 2019 research paper “Flash Boys 2.0 Frontrunning, Transaction Reordering, and Consensus Instability in Decentralized Exchanges” by Phil Daian and others, the term was later changed to reflect the growing value that could be extracted through these strategies as the DeFi ecosystem expanded.

你可知道？最大可提取值曾經稱為礦工可提取值。菲爾·戴安（Phil Daian）和其他人在2019年的研究論文“ Flash Boys 2.0 Frontrunt，交易重新訂購和分散交流中的共識不穩定”中首次引入，後來更改了該術語，以反映可以通過這些策略提取的增長價值作為Defi Ecosystem的增長價值。擴展。

How sandwich attacks work: A step-by-step example

三明治攻擊的工作方式：一個逐步的例子

The mechanics of a sandwich attack involve manipulating the price of an asset before and after a victim’s trade, using buy and sell orders strategically placed in the transaction queue.

三明治攻擊的機制涉及處理受害者交易前後資產的價格，使用在交易隊列中策略性地放置的買賣訂單。

Let’s break down how a sandwich attack happens, using a simple example.

讓我們用一個簡單的示例分解三明治攻擊是如何發生的。

Imagine you’re a crypto trader looking to buy 100 Ether (ETH) on a decentralized exchange (DEX) like Uniswap. Your large order will likely move the market and raise the price of ETH temporarily. An attacker who has been monitoring the network sees your trade. 

想像一下，您是一名加密貨幣交易者，希望在分散的交易所（DEX）（例如UNISWAP）上購買100 ETHER（ETH）。您的大訂單可能會推動市場並暫時提高ETH的價格。一直在監視網絡的攻擊者看到您的交易。

But how does an attacker predict a large incoming order?

但是，攻擊者如何預測龐大的傳入秩序？

Attackers predict large incoming orders by monitoring the mempool, a public waiting area for unconfirmed blockchain transactions. Every user’s transaction details — like the tokens being traded, amounts, and slippage tolerances — are visible here before being added to a block. 

攻擊者通過監視Mempool（未經證實的區塊鏈交易的公共等候區）來預測大量傳入訂單。每個用戶的交易詳細信息（例如被交易的代幣，金額和滑倒公差）在添加到塊之前都可以看到。

Automated bots scan the mempool for large trades or high slippage tolerances, signaling opportunities for profit. Since transactions aren’t encrypted, attackers (via bots) analyze this data in real-time. 

自動機器人掃描Mempool的大型交易或高滑倒公差，這是盈利的信號。由於未加密交易，因此攻擊者（通過機器人）實時分析了這些數據。

If a transaction looks profitable to manipulate, the attacker can act on it by submitting their own transaction with a higher gas fee, ensuring it’s processed first and exploiting the user’s trade.

如果交易看起來有利可圖，則攻擊者可以通過以較高的汽油費提交自己的交易來對其採取行動，從而確保首先處理並利用用戶的交易。

Now, let’s understand how the attack unfolds:

現在，讓我們了解攻擊的發展方式：

An example in the below image shows a bot spotting a large Saitama token purchase in the mempool and buying the token first, pushing the price up. 

下圖中的一個示例顯示了一個機器人，發現了Mempool中購買的大型Saitama代幣購買，並首先購買了代幣，將價格推高。

The victim, who then purchases the token, ends up paying a higher price. The bot sells the token at this inflated price, earning over $200,000 in profit. The attack was made possible by delaying the victim’s transaction by over a minute.

然後購買令牌的受害者最終要支付更高的價格。該機器人以這個高昂的價格出售令牌，賺取了超過20萬美元的利潤。通過將受害者的交易延遲一分鐘來使襲擊成為可能。

Is MEV always negative?

梅夫總是負面的嗎？

No, MEV is not inherently negative.

不，MEV並不是天生的負面。

While it can be exploited through malicious activities like sandwich attacks, it also has positive aspects. MEV can improve market efficiency by facilitating arbitrage and ensuring timely liquidations. It also provides an additional revenue stream for miners and validators, incentivizing their participation in the network. 

雖然可以通過諸如三明治攻擊之類的惡意活動來利用它，但也有積極的方面。 MEV可以通過促進套利和確保及時清算來提高市場效率。它還為礦工和驗證者提供了額外的收入來源，激勵他們參與網絡。

Furthermore, the pursuit of MEV has driven innovation in areas like blockspace auctions (the competitive process of securing space within a block for your transactions to be included and processed) and privacy-preserving technologies. However, it’s crucial to address the potential impact on traders (as discussed above) to ensure a balanced and sustainable crypto ecosystem.

此外，對MEV的追求驅動了諸如Blockspace拍賣等領域的創新（競爭過程的競爭過程，即包括您的交易，並處理您的交易）和保護隱私技術。但是，要解決對交易者的潛在影響（如上所述）至關重要，以確保平衡和可持續的加密生態系統。

How to prevent sandwich attacks in crypto

如何防止加密中的三明治攻擊

By using slippage tolerance settings, breaking down larger trades, using private transaction services and avoiding high-traffic periods, you can reduce your chances of falling victim to a sandwich attack.

通過使用打滑的容忍設置，分解較大的交易，使用私人交易服務並避免人流時期，您可以減少陷入三明治攻擊的受害者的機會。

Now that you understand how sandwich attacks work, here are some practical tips to avoid falling victim to them.

現在您了解了三明治攻擊的工作原理，這裡有一些實用的技巧，避免陷入困境。

Did you know? Two researchers introduced a game-theoretic approach in their paper titled “Eliminating Sandwich Attacks with the Help of Game Theory,” offering an algorithm that significantly reduces the risk of sandwich attacks, outperforming the auto-slippage method used by major automated market makers like Uniswap. This algorithm effectively minimizes transaction costs while

你可知道？兩名研究人員在其論文中介紹了一種遊戲理論方法，標題為“消除借助遊戲理論來消除三明治攻擊”，提供了一種算法，可顯著降低三明治攻擊的風險，勝過諸如UNISWAP之類的主要自動化營銷商使用的自動脫落方法。該算法有效地最大程度地減少了交易成本