Cross-Chain MEV Mitigation

Enables trustless execution of multi-chain transactions as a single atomic unit. This prevents partial execution attacks where a user's transaction succeeds on one chain but fails on another, leaving them vulnerable to sandwich attacks or stuck assets. Protocols like Chainscore use this to bundle intents across chains, ensuring all-or-nothing settlement.

Decentralized sequencer nodes that coordinate transaction ordering and block building across multiple chains. Key features include:

• Shared mempools: View pending transactions across connected chains to identify cross-chain MEV opportunities.
• Cross-chain block building: Construct blocks on multiple chains simultaneously to enforce fair ordering.
• Threshold cryptography: Uses distributed key generation to sign cross-chain bundles securely.

Techniques to hide transaction intent and data from searchers and validators across chains. This includes:

• Commit-Reveal schemes: Users submit a commitment (hash) of their intent, revealing details only after a secure delay.
• Threshold Encryption: Transaction details are encrypted until a committee of nodes agrees to decrypt them for execution.
• Stealth addresses: Generate unique, one-time addresses for each cross-chain interaction to break heuristic tracking.

A single, sealed-bid auction for block space and ordering across multiple blockchains. This consolidates MEV revenue and redistributes it transparently. Mechanisms include:

• Cross-chain PBS (Proposer-Builder Separation): Builders compete to create the most valuable cross-chain block bundle.
• MEV Smoothing: Redistributes extracted value back to users or to a public good fund, rather than concentrating it with a few validators.

Users submit a declarative intent (e.g., "Swap X for Y at best rate across chains A and B") rather than a precise transaction path. A network of solvers competes to fulfill this intent optimally, abstracting away the complex, MEV-prone execution details from the user. This shifts the MEV risk from the user to the solver network.

Light clients and cryptographic proofs (like zk-SNARKs) are used to verify the state and transaction inclusion of one chain on another. This enables secure, trust-minimized bridging and prevents MEV attacks that rely on invalid or reorged state from a connected chain, a common vector in bridge exploits.

Consensus-level protocols that enforce a canonical, fair ordering of transactions to prevent manipulation. Instead of a single leader (e.g., a block proposer) having full discretion over ordering, these protocols use mechanisms like Byzantine Agreement or leader election to agree on a sequence. This makes it computationally infeasible for any single entity to censor or reorder transactions for profit, mitigating cross-domain MEV opportunities.

A market-based approach that formalizes and auctions off the right to propose cross-chain transaction bundles. Interchain searchers compete in a sealed-bid auction (e.g., using a MEV-Share-like protocol) to submit optimal bundles. The winning bid's value is then redistributed to users or the protocol treasury. This transforms opaque extraction into a transparent revenue stream, reducing the negative externalities of gas-gaming and arbitrage races.

A two-phase protocol where users first commit to a transaction (e.g., by submitting a hash) on one chain and later reveal the full details on the destination chain. This creates a binding commitment that prevents searchers from front-running the revealed transaction, as its outcome is already determined. It is particularly effective for mitigating MEV in atomic cross-chain swaps and bridge operations, though it introduces latency.

A dedicated layer that sequences transactions for multiple rollups or execution environments before they are settled on a base layer (like Ethereum). By having a single, shared sequencer set with enforceable rules (e.g., first-come, first-served ordering), it eliminates MEV opportunities that arise from the fragmented sequencing across individual rollups. This is a key proposal for mitigating cross-rollup MEV in a modular blockchain ecosystem.

Decentralized monitoring systems that detect and potentially punish malicious cross-chain MEV extraction. Watchtowers analyze transaction flows across chains, flagging patterns indicative of sandwich attacks or time-bandit attacks on bridges. While not a prevention mechanism, detection creates reputational risk for bad actors and provides data to refine other mitigations. These networks often contribute to public MEV dashboards and analytics.

An extension of PBS (Proposer-Builder Separation) to a multi-chain environment. Specialized cross-chain block builders compete to construct optimal blocks across multiple chains simultaneously. This can mitigate MEV by:

• Internalizing arbitrage: The builder captures cross-chain arbitrage value directly and can share it with chain validators/proposers via payments.
• Reducing latency races: By coordinating execution across chains in a single entity, it reduces the wasteful gas auction competition between independent searchers on each chain.
• Increasing economic efficiency of cross-chain value flow.

The primary risk where an attacker observes a pending cross-chain transaction (e.g., a large swap) on the source chain and races to execute a similar transaction on the destination chain first, profiting from the price impact. This exploits the latency between block finality on the source chain and message relay to the destination. Mitigations include using private mempools (like SUAVE) for the initial transaction or implementing commit-reveal schemes.

In many cross-chain systems, a small set of validators or relayers are responsible for attesting to and forwarding state updates. These entities can collude to censor, reorder, or withhold transactions to extract MEV. This centralization risk is fundamental to many bridge designs. Solutions involve increasing validator set decentralization, using fraud proofs, or employing threshold cryptography to require a higher number of signers.

A specific form of MEV where the order of messages arriving at a destination chain is manipulated. For example, if two cross-chain swap requests are sent, a malicious relayer can order them to maximize their own arbitrage profit. This attacks the temporal consistency guarantees of the bridge. Protocols like Chainlink CCIP implement a strict FIFO (First-In-First-Out) ordering to prevent this.

Occurs when an attacker exploits the liquidity pools on both sides of a bridge. They front-run a user's deposit into a bridge pool on Chain A, then back-run the corresponding withdrawal on Chain B, sandwiching the user's transaction. This is prevalent in liquidity network bridges (e.g., some implementations of Stargate). Mitigation requires sophisticated batch processing and uniform clearing prices for all transactions in a batch.

Cross-chain actions often rely on oracles for price feeds or proof verification. An attacker can manipulate the oracle's reported data on one chain to create a profitable, risk-free arbitrage opportunity on another. For instance, temporarily inflating the reported price of an asset on Chain A could allow for an undervalued minting of a synthetic asset on Chain B. Using decentralized, delay-resistant oracle networks is critical.

Maximal Extractable Value (MEV) is the total profit that can be extracted by reordering, including, or censoring transactions within a block, beyond standard block rewards and gas fees. It arises from the ability of block producers (validators, miners) to manipulate transaction order.

• Sources: Arbitrage, liquidations, front-running, and sandwich attacks.
• Impact: Can lead to network congestion, higher gas fees, and a degraded user experience.

Cross-chain bridges are protocols that enable the transfer of assets and data between distinct blockchain networks. They are the primary vector for cross-chain MEV, as transactions on the source and destination chains create arbitrage opportunities.

• Key Protocols: Wormhole, LayerZero, Axelar.
• Vulnerability: The time delay between a transaction being initiated on one chain and finalized on another creates a window for exploitation.

Threshold Encryption is a cryptographic technique where a transaction is encrypted and can only be decrypted by a decentralized network of nodes (a "threshold") after a fair ordering has been established. This blinds the transaction content from block builders.

• Process: 1) User encrypts transaction. 2) FSS orders the ciphertext. 3) Threshold network decrypts it only after ordering.
• Purpose: Prevents builders from seeing transaction details they could exploit, neutralizing front-running and sandwich attacks.

Cross-chain arbitrage is the practice of exploiting price differences for the same asset (e.g., ETH, USDC) across different blockchain networks. It is a primary source of cross-chain MEV.

• Mechanism: A trader monitors a bridge for large pending transfers, then quickly executes trades on the destination chain's DEXs before the bridged funds arrive, profiting from the anticipated price impact.
• Mitigation: Encrypted mempools and FSS aim to hide the intent and size of bridge transactions to prevent this.