StarkWare Validates Post-Quantum Scheme QSB on Bitcoin Mainnet Without a Soft Fork, But Lacks General-Purpose Viability for Now

On October 9, according to an official Starknet disclosure, StarkWare developers successfully spent a Quantum-Safe Bitcoin (QSB) output using a hash-based quantum-resistant scheme on the Bitcoin mainnet without a soft fork. Executed at block height 964,199, the transaction consumed approximately several hundred dollars in GPU computing power and was directly submitted to the chain via mining firm MARA's Slipstream service.

The QSB framework utilizes existing Bitcoin script rules, replacing the traditional elliptic curve private key unlocking mechanism with hash computations and hash-based one-time signatures to protect outputs from threats posed by Shor's algorithm. However, StarkWare points out that QSB transactions are non-standard and computationally expensive, serving only as a stopgap measure for emergencies and research. Bitcoin's genuine quantum-resilient path still depends on a soft fork that introduces post-quantum signatures.

Furthermore, during Token2049, StarkWare CEO Eli Ben-Sasson emphasized that blockchain networks require the agility to dynamically update cryptographic protocols as threats evolve. Given that Starknet's full quantum security as a Layer 2 network is reliant on Ethereum, Ben-Sasson posed a question to the community, openly exploring whether Starknet should transition to a Layer 1 in the future to enable an autonomous, agile migration to post-quantum standards.