Post-quantum security is irrelevant for current rollup economics. The primary bottleneck for Arbitrum, Optimism, and StarkNet is prover cost and data availability, not a quantum attack that is decades away from feasibility.
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STARKs' Post-Quantum Promise is a Distraction for Current Rollups
An analysis of why prioritizing post-quantum security in L2s like Starknet and zkSync introduces premature complexity and cost, distracting from more pressing optimizations in proving speed and cost for Ethereum scaling.
introduction
THE REALITY CHECK
Introduction
The post-quantum narrative for STARKs is a long-term theoretical hedge that distracts from the immediate scaling and cost challenges facing rollups like Arbitrum and zkSync.
STARKs' real advantage is recursion. Their quantum-resistant design is a byproduct of using hash functions, but the immediate value is in efficient proof composition for validiums and Volition architectures, not future-proofing.
The distraction costs resources. Engineering focus on post-quantum cryptography diverts talent from solving prover performance and Ethereum calldata costs, which are the existential constraints for today's rollup users.
thesis-statement
THE DISTRACTION
The Core Argument: Premature Optimization is the Root of All Overhead
STARKs' post-quantum security is a theoretical hedge that introduces unnecessary complexity and cost for today's rollups.
Post-quantum cryptography is irrelevant for the next decade. The threat model for Ethereum rollups like Arbitrum and Optimism is classical compute, not quantum attacks. Engineering resources spent on this edge case divert from solving real scaling bottlenecks.
ZK-STARKs introduce operational overhead that SNARKs like Plonky2 or Halo2 avoid. STARK proofs are larger, generating more calldata costs on L1. This directly increases transaction fees for users without a tangible security benefit.
The real optimization frontier is cost, not quantum resistance. Projects like Polygon zkEVM and zkSync Era prioritize SNARK recursion and GPU provers to lower fees. STARKs' mathematical elegance is a premature optimization that sacrifices immediate user experience.
key-trends
POST-QUANTUM CRYPTO IS A RED HERRING
The Real Battlegrounds: Where L2s Should Focus
While STARKs offer long-term quantum resistance, today's rollups are losing the war on user experience, developer adoption, and economic security.
01
The Problem: Prover Centralization
The real security risk isn't quantum computers in 2030, it's a single point of failure in the prover network today. A single sequencer-prover like in many rollups creates a centralization vector that quantum resistance can't fix.
- Key Risk: A malicious or faulty prover can halt the chain or censor transactions.
- Key Benefit: A decentralized prover network (e.g., EigenDA, Espresso) provides liveness guarantees and censorship resistance now.
1
Single Point of Failure
~0s
Censorship Latency
02
The Problem: Fragmented Liquidity & UX
Users don't care about quantum bits; they care about moving assets between Arbitrum, Optimism, and Base without 7-day delays or paying $50 in fees. This is the actual adoption bottleneck.
- Key Benefit: Native cross-rollup interoperability (e.g., LayerZero, Chainlink CCIP) enables seamless composability.
- Key Benefit: Shared sequencing layers (e.g., Espresso, Astria) enable atomic cross-rollup transactions.
7 Days
Withdrawal Delay
$10B+
Fragmented TVL
03
The Problem: Data Availability Cost
Over 90% of a rollup's transaction cost is posting data to Ethereum. Chasing exotic cryptography ignores the dominant cost center that directly impacts user growth.
- Key Benefit: EigenDA and Celestia offer ~100x cheaper data availability, slashing L2 fees.
- Key Benefit: Efficient data compression (e.g., zk-compression) reduces calldata bloat without waiting for quantum-proof systems.
90%
Cost is Data
100x
Cheaper DA
04
The Problem: Sequencer Extractable Value (SEV)
While MEV is well-known, centralized sequencers capture Sequencer Extractable Value (SEV) through transaction ordering and latency arbitrage. This is a multi-billion dollar leakage today.
- Key Benefit: Decentralized sequencer sets (e.g., SUAVE, Shutter Network) democratize ordering and protect users.
- Key Benefit: Encrypted mempools prevent frontrunning, a more immediate threat than quantum decryption.
$B+
Annual SEV
~500ms
Arbitrage Window
05
The Problem: State Growth & Synchronization
Rollup state grows infinitely, making new node synchronization impossible for average users. A quantum-secure chain no one can verify is useless.
- Key Benefit: Stateless clients and Verkle trees (coming to Ethereum) enable lightweight verification.
- Key Benefit: zk-SNARKs for state proofs (like RISC Zero) allow trustless syncing from a checkpoint, solving today's problem.
TB+
State Size
Days
Sync Time
06
The Problem: Developer Tooling Fragmentation
Building a multi-chain dapp across zkSync, Scroll, and Starknet is a nightmare of different VMs and SDKs. This stifles innovation more than any cryptographic threat.
- Key Benefit: Unified execution layers (e.g., EVM equivalence, WASM) reduce developer friction.
- Key Benefit: Standardized cross-chain APIs (e.g., Polygon AggLayer, Hyperlane) abstract away the underlying rollup.
5+
Different VMs
10x
Dev Time Increase
THE REALITY CHECK
Proving System Trade-Offs: The Quantum Premium
A quantitative comparison of proving systems, highlighting that STARKs' post-quantum security is a costly, premature optimization for current rollups.
| Feature / Metric | STARKs (e.g., Starknet) | SNARKs (e.g., zkSync, Scroll) | Validity Proofs (General) |
|---|---|---|---|
Post-Quantum Security (Lattice-based) | |||
Proving Time for 1M TX Batch | ~10 minutes | ~3 minutes | Varies by construction |
Verification Gas Cost on L1 | ~600k gas | ~200k gas | Dependent on circuit |
Trusted Setup Required | SNARKs: Yes, STARKs: No | ||
Proof Size (KB) | 45-100 KB | ~1 KB | STARKs: Larger, SNARKs: Compact |
Primary Bottleneck | Prover Compute & Memory | Prover Memory & Trusted Setup | Circuit Design & Optimization |
Ecosystem Tooling Maturity | Emerging (Cairo) | Mature (Circom, Halo2) | Rapidly evolving |
Practical Threat Horizon |
|
| Same for all cryptographic primitives in use |
deep-dive
THE REAL THREAT
Deconstructing the Security Model: Why L1 is the Weakest Link
Rollup security is bottlenecked by L1 finality and data availability, making post-quantum cryptography a premature optimization.
Post-quantum cryptography is irrelevant for current rollup security. The primary attack vector is not a quantum computer breaking ECDSA, but a malicious sequencer withholding data or exploiting slow L1 finality. Projects like Arbitrum and Optimism inherit the security faults of their underlying L1, not the cryptographic primitives.
The weakest link is L1 finality. A rollup's state root posted to Ethereum is only as secure as Ethereum's probabilistic finality, which takes ~12 minutes. This creates a massive window for malicious sequencers to execute data withholding attacks before fraud proofs can be submitted, a vulnerability STARKs cannot solve.
Data availability is the true bottleneck. Even with a ZK-proof, a rollup like zkSync or StarkNet is insecure if its data is not posted and verifiable on-chain. The industry's focus should be on validiums and EigenDA, which address the real constraint, not a theoretical quantum threat decades away.
Evidence: Ethereum's 12-minute finality delay is 10,000x longer than the time needed to generate a STARK proof. Security is defined by the slowest component in the system, which is unequivocally the base layer's consensus.
counter-argument
THE LONG GAME
Steelman: "Future-Proofing is Prudent"
Acknowledging the theoretical quantum threat is a responsible hedge against catastrophic protocol failure.
Quantum resistance is non-negotiable for finality. A future quantum computer breaking ECDSA would shatter the cryptographic foundation of every L1 and L2 today, invalidating all security assumptions. STARKs' reliance on hash functions like SHA-256 is the only major ZK system with proven post-quantum security.
Early adoption builds critical expertise. Projects like StarkWare and Polygon Miden are developing this muscle now. Their work on STARK toolchains (Cairo, Miden VM) creates a defensible long-term technical moat that SNARK-focused teams like Scroll or zkSync lack.
The distraction argument is a false trade-off. Teams are not choosing between optimizing for today or tomorrow; they are building general-purpose provers. A STARK prover built for today's hardware (e.g., using SHARP) also works for tomorrow's threats. The marginal cost of future-proofing shrinks over time.
Evidence: Ethereum's roadmap explicitly prioritizes post-quantum security for its consensus layer. Ignoring this vector is a bet against the survival of the entire ecosystem, not just an individual rollup.
takeaways
STARKs vs. PRACTICALITY
Executive Summary: 3 Takeaways for Builders
Theoretical post-quantum security is a long-term hedge, not a current scaling bottleneck. Here's where your engineering resources should go.
01
The Quantum Threat Timeline is a Decadal Hedge
Practical quantum computers capable of breaking ECDSA are 15-30 years away. The real threat to rollups today is centralization and high operating costs, not a cryptographically irrelevant adversary.
- Focus on Sequencer Decentralization: The immediate attack vector.
- Optimize Prover Costs: The ~10-100x cost delta between STARKs and SNARKs matters more for $1B+ TVL systems.
- Audit Your Current Stack: A bug in your bridge or multisig is a more probable failure mode.
15-30y
Threat Horizon
10-100x
Cost Premium
02
ZK-Rollup Throughput is Gated by Hardware, Not Cryptography
The bottleneck for Starknet, zkSync Era, Polygon zkEVM is prover time and cost, not the underlying proof system's PQ-resistance. STARKs require more computational work, slowing finality.
- Prioritize GPU/ASIC Provers: This reduces proof times from ~10 minutes to ~1 minute.
- Adopt Recursive Proofs: Aggregating proofs (like Polygon's Plonky2) cuts on-chain verification cost by ~90%.
- Ignore PQ, Optimize for Today's Hardware: The ~500ms latency target for real DeFi is a hardware problem.
~10min
Prover Time
-90%
Verif. Cost
03
Interoperability Fragmentation is a Clearer and Present Danger
A post-quantum secure rollup is useless if it's a silo. The ecosystem risk is fragmented liquidity across 50+ L2s, not a quantum break of one chain.
- Build with Universal Proof Systems: Choose systems compatible with EigenDA, Celestia, or Avail for shared security.
- Integrate Intent-Based Bridges: Protocols like Across, LayerZero, and Connext abstract liquidity fragmentation.
- Standardize State Proofs: Enable light clients to verify your chain, making Celestia-style data availability the critical security layer.
50+
L2 Silos
$10B+
Bridged TVL
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