Rollups Shift Risk to Operators

A single, centralized sequencer controls transaction ordering and censorship. This creates a single point of failure for liveness and MEV extraction.\n- Liveness Risk: If the sequencer goes offline, the chain halts.\n- Censorship Risk: The operator can arbitrarily exclude transactions.\n- Economic Risk: Users are forced to trust the operator's economic fairness.

The entity generating validity or fraud proofs holds the keys to state correctness. A malicious or faulty prover can steal funds or halt withdrawals.\n- Technical Risk: Complex proving systems (ZK) have high setup and operational complexity.\n- Centralization Risk: Proving is often a monopolized service due to hardware/engineering costs.\n- Window of Risk: In optimistic rollups, the 7-day challenge period is a liquidity lock and attack vector.

The canonical bridge is controlled by a multi-sig or a small set of operators. This creates a massive, centralized honeypot for cross-chain assets.\n- Custodial Risk: Bridge keys control all locked funds on L1.\n- Upgrade Risk: Admin keys can arbitrarily change bridge logic.\n- Interop Risk: This model breaks the trust-minimized promise of Ethereum L1 security, as seen in exploits against Wormhole and Polygon Bridge.

The Problem: A single sequencer is a central point of failure for censorship and liveness. The Solution: A shared, decentralized sequencer network using HotShot consensus, enabling fast finality (~2 seconds) and MEV redistribution.

• Shared Sequencing: Enables atomic cross-rollup composability.
• Proof-of-Stake Security: Sequencers stake to participate, slashed for misbehavior.

The Problem: Every rollup team reinvents the wheel on sequencing, a massive security and operational burden. The Solution: A permissionless, shared sequencer network that rollups plug into, turning sequencing into a commoditized service.

• Decentralized from Day 1: No centralized operator, reducing regulatory and technical risk.
• Rollup-Agnostic: Supports any execution environment (EVM, SVM, Cairo).

The Problem: The security of a rollup's bridge (L1 state root verification) is its ultimate vulnerability. The Solution: Succinct SP1 enables cost-effective, high-performance ZK proofs for any VM, making trust-minimized bridges practical.

• General-Purpose ZK: Prove correct state transitions for Rust, EVM, or custom VMs.
• Reduces Exit Window: Enables near-instant, cryptographically secure withdrawals.

The Problem: New protocols (like decentralized sequencers, oracles, AVSs) must bootstrap their own expensive security. The Solution: EigenLayer allows ETH stakers to opt-in to secure additional services, creating a pooled security marketplace.

• Capital Efficiency: Staked ETH secures both Ethereum and new AVSs.
• Slashing for Liveness: Operators are financially penalized for downtime or censorship.

The Problem: Posting transaction data to Ethereum L1 is the dominant cost for rollups and a potential censorship vector. The Solution: NEAR Protocol acts as a high-throughput, low-cost data availability layer, secured by its own sharded Proof-of-Stake network.

• ~$0.003 per 100KB: Orders of magnitude cheaper than Ethereum calldata.
• Ethereum Finality: Data posted to NEAR is provably available with Ethereum settlement.

The Problem: Rollup security is fragmented, creating systemic risk and poor user experience. The Solution: A competitive stack is emerging: Espresso/Astria for sequencing, EigenLayer for cryptoeconomic security, Celestia/Near DA for data, Succinct/zkSync for proofs.

• Winner-Takes-Most: The most secure, cost-effective stack will attract dominant rollups.
• Modular Risk: Operators can now specialize and insure specific failure modes.

Rollups like Arbitrum and Optimism rely on a single, centralized sequencer for transaction ordering and inclusion. This creates a critical liveness and censorship risk.

• Liveness Risk: If the sequencer goes down, the chain halts.
• Censorship Risk: The operator can front-run or exclude transactions.
• Economic Centralization: Profits from MEV and fees are concentrated.

In ZK-Rollups like zkSync Era and Starknet, the separation between the Proposer (sequencer) and Prover introduces a new attack vector. A malicious actor controlling both can steal funds.

• Invalid State Transition: A colluding prover can generate a fake validity proof for a fraudulent batch.
• Escape Hatches: Users must rely on slow fraud proofs or forced transaction exits via L1.
• Trust Assumption: Security reverts to a 7-day challenge window, not instant finality.

Celestia, EigenDA, and Avail aim to solve data availability, but rollups that post data off-chain (e.g., Validium mode) trade scalability for a catastrophic failure mode.

• Data Withholding: If the operator withholds transaction data, the rollup state cannot be reconstructed.
• Funds Frozen: Users cannot prove ownership or exit.
• Modular Stack Risk: Introduces dependency on a separate, potentially unstable DA layer.

Projects like Espresso and Astria propose decentralized sequencer sets shared across rollups. This mitigates single-chain liveness risk but creates new cross-chain systemic risk.

• Cross-Rollup MEV: A sequencer set can now extract MEV across multiple chains simultaneously.
• Cartel Formation: Sequencers may collude to maximize extractable value.
• Complexity Trade-off: Replaces operator risk with cryptoeconomic consensus risk, which is untested at scale.