Why Smart Account Signature Aggregation Is Still a Pipe Dream

Aggregating signatures off-chain is cheap, but the on-chain verification is what matters. The dominant BLS signature scheme requires heavy elliptic curve pairing operations, costing ~200k+ gas per verification in a batch. For a batch of 1000 accounts, you still pay for the computation, negating most savings versus individual ECDSA checks.

• Gas Cost: Verification scales linearly with signers in practice.
• Throughput: Bottlenecked by Ethereum's ~30M gas/block limit.
• Example: StarkWare's SHARP prover handles this off-chain, but that's a centralized sequencer, not a pure smart contract.

To be practical, aggregation requires a coordinator (e.g., a bundler) to collect signatures. This creates a critical liveness dependency and re-centralization risk.

• Single Point of Failure: If the aggregator is down, your "gasless" transaction is stuck.
• MEV Extraction: The aggregator becomes a powerful MEV searcher, akin to Flashbots validators.
• Protocols at Risk: Account abstraction systems like EIP-4337 Bundlers and Safe{Wallet} modules must design around this trusted role.

Signature aggregation isn't a protocol standard; it's an implementation detail. Each smart account wallet (Safe, Biconomy, Argent) and rollup (Starknet with native account abstraction) may use different schemes.

• No Interoperability: A signature aggregated for Safe cannot be used by an Argent session key.
• Developer Hell: dApps must integrate multiple signature verifiers, defeating the simplicity promise.
• Ecosystem Silos: This fragmentation mirrors the early ERC-20 approval chaos, stalling network effects.

The viable path is pushing aggregation into the execution layer where gas costs are negligible. Rollups like Starknet, zkSync Era, and Optimism can implement native signature aggregation in their state transition functions.

• Native Efficiency: The sequencer handles aggregation off-chain, with validity proven via ZK or fraud proofs.
• User Experience: Truly gasless, instant transactions become possible within the L2.
• Future Vision: This aligns with the Ethereum roadmap of L1 for security/settlement and L2 for execution/innovation.

Instead of burdening Ethereum L1, delegate verification to a separate, optimized chain. EigenLayer AVSs or Celestia-fueled rollups can act as signature aggregation co-processors.

• Purpose-Built: A chain optimized only for BLS operations can be orders of magnitude cheaper.
• Sovereign Verification: The aggregated proof is then posted back to Ethereum as a single, cheap verification.
• Parallels: Similar to how Polygon Avail or EigenDA handle data availability separately from execution.

Give up on synchronous "one-block" finality for non-critical operations. Use a system like Chainlink Functions or The Graph to aggregate signatures over minutes or hours, then submit a proven batch.

• Real-World Use: Perfect for social recovery actions, DAO votes, or scheduled payroll.
• Cost Elimination: Amortizes cost over thousands of actions, potentially driving cost per signature to ~$0.
• Trade-Off: Accepts latency for radical cost reduction, a pattern seen in Optimism's fault proof window.

Universal signature schemes like BLS require a coordinated ecosystem fork. Getting every wallet provider (MetaMask, Rabby, Rainbow), every L2 (Arbitrum, Optimism, Base), and every dApp to upgrade simultaneously is a political impossibility.\n- Network Effect Lock-in: EOA/secp256k1 has ~$1T+ in secured assets and decades of tooling.\n- Coordination Failure: A single major holdout (e.g., a top CEX) breaks the universal interoperability promise.

BLS is often touted for its post-quantum security, but this is a distraction. The real threat model for smart accounts today is social engineering and key management, not Shor's algorithm.\n- Premature Optimization: Quantum computers capable of breaking ECDSA are decades away for crypto-sized keys.\n- Real Risk Today: Users lose funds to phishing and seed phrase mismanagement, not theoretical attacks.

ERC-4337 Bundlers already aggregate user operations off-chain, achieving ~80% of the scaling benefits without a consensus-layer change. This is the deployable path.\n- Incremental Adoption: Works with existing EOAs and secp256k1 today via signature abstraction.\n- Proven Scale: Bundlers can batch hundreds of ops into one on-chain transaction, reducing L2 gas costs by ~30-50% for users.

BLS aggregation often requires a trusted setup or a centralized aggregator/verifier node to combine signatures. This recreates the trusted third-party problem crypto aims to solve.\n- New Trust Assumption: Projects like Succinct Labs are working on trustless proof generation, but it adds ~500ms-2s latency and significant proving cost.\n- Single Point of Failure: A malicious or faulty aggregator can censor or corrupt the entire batch.

Even if an L2 ecosystem adopts BLS, cross-chain messages break the model. Bridges like LayerZero, Axelar, and Wormhole would need to support the new signature type, adding years to the rollout timeline.\n- Interop Complexity: A user's aggregated signature on Arbitrum is meaningless on Polygon without a complex, slow attestation bridge.\n- Liquidity Fragmentation: Aggregated accounts would be stranded on their native chain, defeating the purpose of a multichain world.

The marginal benefit of on-chain BLS aggregation over off-chain batching via ERC-4337 does not justify the catastrophic coordination cost. Engineering effort is better spent on social recovery, session keys, and policy engines.\n- Real User Benefit: Seedless recovery and gas sponsorship drive adoption, not cryptographic purity.\n- Resource Allocation: Teams building BLS today are solving a 2030s problem while 2024's problems remain unsolved.