🚀Preventing MEV

MEV Sandwich Attack is an attack strategy that leverages MEV (Maximizing Extractable Value), where attackers attempt to insert their transactions around a target user's transaction to maximize their profits. This attack typically occurs on DEX platforms.

The attack steps are as follows:

1. Detection: Attackers initially monitor the blockchain network, particularly focusing on upcoming transactions, especially large or high-profit transactions.

2. Insertion: Once a target user's transaction is identified, attackers rapidly submit a series of their own transactions. The first transaction usually occurs before the target user's transaction, while the second transaction occurs after.

3. Squeeze: The attacker's first transaction typically affects market prices, resulting in unfavorable prices for the target user's transaction. The second transaction then utilizes the target user's transaction to push market prices back to normal, allowing the attacker to profit from the trade.

MEV Sandwich Attack fully exploits transaction execution order and market price volatility on the blockchain. To mitigate this attack, some platforms employ various measures such as optimizing transaction execution order, introducing transaction matching mechanisms, and implementing fee limits to reduce the attacker's profit margins.

In cross-chain interoperability protocols, especially those involving multiple blockchain networks, there is also a risk of being targeted by MEV (Maximizing Extractable Value) attacks. MEV attacks are not limited to transactions on a single chain but can affect transaction order and prices across multiple chains through cross-chain operations.

MEV attacks in cross-chain interoperability protocols adopt similar tactics to the sandwich attack, inserting their transactions around a target user's cross-chain transactions to maximize profits. Attackers can monitor users about to perform cross-chain operations, especially those involving large sums of money. Once such targets are identified, attackers can insert their transactions before and after the user's transaction to maximize their gains by adjusting market prices.

Intent-based cross-chain design can effectively prevent MEV attacks by concealing Calldata in Solver's solution, using a private transaction mempool, thereby reducing attackers' opportunities for information acquisition and manipulation. This privacy protection measure provides an additional layer of security, helping to ensure the fairness and user interests of cross-chain operations.

However, most cross-chain protocols that do not adopt intent-based designs cannot achieve this because even if the Calldata of the target chain is placed in a private transaction mempool, attackers can still infer the execution order of cross-chain transactions to the target chain by analyzing the Calldata on the source chain. In this case, MEV attackers can manipulate and prioritize cross-chain transactions using information from the source chain.

Adopting intent-based cross-chain design by parsing and solving user intents off-chain keeps transaction execution details in a private off-chain space, avoiding the public exposure of source chain Calldata, thereby enhancing the protocol's security. This design partly addresses the issues caused by MEV attacks, providing cross-chain protocols with more reliable security and user privacy protection.