StarkWare Unveils Starknet Quantum-Resistance Roadmap, Urges Industry to Act

Bitcoin relies on elliptic-curve signatures to authorize spending, leaving coins potentially exposed if a sufficiently powerful quantum computer uses Shor’s algorithm to derive private keys. The risk is greatest for addresses whose public keys are already visible and during the confirmation window after a holder broadcasts a transaction. Coinbase’s quantum advisory council estimated in June 2026 that roughly 7 million BTC could be vulnerable because of exposed public keys and address reuse, sharpening calls for a network-wide migration.

On Aug. 26, StarkWare said its Quantum-Safe Bitcoin (QSB) transaction was confirmed in mainnet block 964,199, spending a 10,000-satoshi output. The test took hours of computation and cost about $150 to $200; because the format is nonstandard, it was submitted directly to MARA Pool through Slipstream. QSB, proposed by StarkWare researcher Avihu Levy in April, combines hash-based one-time signatures with “signature grinding.” StarkWare said the method protects individual transactions but not already-exposed public keys, and still favors a protocol-level soft fork for comprehensive protection.

Bitcoin’s current Elliptic Curve Digital Signature Algorithm, or ECDSA, could eventually be vulnerable to quantum computers, requiring the adoption of post-quantum signatures approved by the U.S. National Institute of Standards and Technology. But the new signatures are 10 to 100 times larger than those now in use. Adding them directly would cause blockchain data to surge, undermine decentralization and sharply reduce transaction speeds, leaving the Bitcoin network with a difficult trade-off between quantum security and operational efficiency.

In July 2026, a StarkWare co-founder said a better approach would be to use ZK-STARKs to aggregate multiple post-quantum signatures into a single proof instead of expanding block capacity from the current 4MB to 32–64 MiB. That same month, StarkWare also unveiled a three-stage upgrade plan for Starknet and began studying a fork-free solution with estimated computational costs of $75–$150 per transaction to protect against quantum-security threats.

Bitcoin transactions rely on elliptic-curve digital signatures. A sufficiently powerful quantum computer running Shor’s algorithm could derive private keys from exposed public keys and steal assets. Replacing the signature mechanism would require network-wide consensus and asset migration, drawing attention to StarkWare’s upgrade-free approach as a fallback until longer-term changes such as BIP-360 are completed.

On April 9, 2026, StarkWare Chief Product Officer and BIP-360 co-author Avihu Levy published the QSB paper and open-source code. The system uses Bitcoin’s existing Script constraints and hash-based proofs to create quantum-resistant transactions without a soft fork or miner activation. Each transaction requires substantial offline GPU computation at an estimated cost of $75–$200, and the tool is currently intended for emergency recovery.

Quantum computers could break Ethereum’s current elliptic-curve cryptography, threatening validator consensus, account signatures and onchain assets. Vitalik Buterin has identified four vulnerable areas in the protocol, including BLS signatures and KZG commitments. Upgrading Ethereum for quantum resistance is therefore critical to its long-term security and the protection of assets on the network.

Buterin has unveiled a comprehensive roadmap, while the Ethereum Foundation has formed a dedicated Post-Quantum team with the goal of completing protocol-level upgrades by 2029. The proposed measures include replacing vulnerable mechanisms with STARK proofs, introducing hash-based signatures into Lean consensus and exploring the use of SNARKs to reduce the performance burden of quantum-safe cryptography.