Why Multi-Party Computation Is Too Cumbersome for Real-Time Deals

MPC's core security mechanism—distributed key generation and signing across multiple parties—introduces unavoidable network round-trip delays. This creates a fundamental trade-off between security quorums and speed.

• Consensus Rounds add ~500ms-2s of latency per signature.
• Geographic Distribution of nodes for censorship resistance compounds the delay.
• Makes MPC untenable for arbitrage, liquidations, or real-time auctions.

Operational costs scale linearly with the number of participants and signing frequency. Each node in the MPC network represents a persistent, compensated infrastructure cost.

• Node Operator Fees create a ~$0.50-$5+ variable cost per transaction.
• High Throughput for DeFi or gaming becomes prohibitively expensive versus a smart contract wallet.
• Eclipses the gas savings intent-based systems like UniswapX or CowSwap aim to provide.

MPC requires continuous, fault-tolerant communication between nodes. Managing this orchestration layer adds complexity and creates single points of failure in the coordination logic itself.

• Node Availability must be near-perfect (>99.9% SLA), requiring expensive redundancy.
• Key Refresh Protocols are computationally intensive and disrupt operations.
• Contrast with simpler architectures like account abstraction bundlers or intent solvers.

MPC wallets are often black-box systems. Integrating complex, conditional transaction logic—like those required for intent-based bridging (Across) or limit orders—requires custom, off-chain coordination layers.

• Lacks Native Composability with on-chain smart contracts and oracles.
• Business Logic must be duplicated off-chain, creating security and sync risks.
• Smart Contract Wallets (ERC-4337) and solvers are inherently more programmable.

Every signature requires a multi-round communication protocol between geographically distributed nodes. This creates inherent latency and a single point of failure in the coordination layer.

• Latency: Finality takes ~2-5 seconds, unacceptable for DEX arbitrage or liquidations.
• Liveness Risk: If 1 node goes offline, the entire signing ceremony stalls.
• Cost: Operational overhead scales with the number of signers and transaction volume.

Shift the burden of execution from user transactions to a network of competing solvers. Users submit signed intent messages (off-chain), and solvers compete to fulfill them optimally on-chain.

• Speed: User experience is sub-second; settlement is batched and asynchronous.
• Cost: No failed transaction fees; solvers absorb gas costs.
• Efficiency: Enables MEV capture and redistribution back to users via better prices.

Use a lightweight, fast messaging layer with a fraud-proof window. A single attester/relayer provides instant guarantees, with a fallback to a slower, more secure verification chain if a challenge is issued.

• Real-Time: ~500ms latency for cross-chain messages.
• Secure: Economic security backed by bonded validators on the slow chain (e.g., Ethereum).
• Modular: Decouples liveness (fast lane) from safety (slow lane).

Delegate transaction authority via a signed user op to a dedicated bundler network. The bundler handles gas, nonce management, and inclusion, acting as a high-performance transaction coordinator.

• User Experience: Gasless interactions and batch transactions.
• Throughput: Bundlers can order and submit 1000s of UserOps in a single bundle.
• Composability: The standard enables a competitive network of bundlers, similar to block builders.

MPC's multi-round protocols for signing or decryption introduce ~100ms-2s of latency per operation. This is fatal for MEV-sensitive trades competing in sub-second blocks on chains like Solana or Arbitrum.\n- Unacceptable for DEX Aggregation: UniswapX intents require near-instant signature validation.\n- Breaks Composable DeFi: Lags cascade through flash loans and multi-hop swaps.

MPC requires continuous, coordinated online presence of multiple parties, creating a coordination and liveness nightmare. In contrast, a Trusted Execution Environment (TEE) like Intel SGX is a single, always-available enclave.\n- No Live Coordination: TEEs process requests instantly, like a server.\n- Simpler Key Management: One secure enclave vs. distributed key shards.

The computational and bandwidth overhead of MPC protocols translates directly to 10-100x higher operational costs compared to TEE-based or optimistic systems. This cost is passed to users, killing margin in high-volume, low-fee environments.\n- Bandwidth Intensive: Constant peer-to-peer communication between nodes.\n- Compute Heavy: Complex cryptographic operations per transaction.

MPC shifts trust from a single entity to a committee, but now you must trust all committee members. For real-time deals, you need a verifiable, deterministic result—not a probabilistic one. Systems like Across Protocol's optimistic verification or TEE attestations provide this faster and cheaper.\n- Deterministic Output: TEE attestation is a cryptographic proof of correct execution.\n- No Committee Delays: Verification is asynchronous and fast.

Modern intent-based systems (UniswapX, CowSwap, Across) rely on fillers competing on speed and price. An MPC-based solver would always lose to a TEE-based or centralized filler due to latency. The market selects for pragmatism.\n- Filler Competition: Latency is a direct competitive disadvantage.\n- Architectural Mismatch: MPC is for custody, not real-time auction engines.

The winning infrastructure for real-time deals combines TEEs for speed and privacy with fraud proofs or attestation for security. This hybrid model, seen in projects like Phala Network and Oasis, offers ~99% of MPC's security with orders-of-magnitude better performance.\n- Speed Layer: TEE handles instant execution.\n- Security Layer: Fraud proofs or attestations settle disputes.