Starknet outlines QSB for Bitcoin, says StarkWare researchers tested it on mainnet
Starknet has introduced a quantum-safe Bitcoin approach called QSB, saying StarkWare researchers validated the mechanism on Bitcoin mainnet without requiring a soft fork, new opcodes, or changes to consensus rules. According to the post, the first QSB output was spent on Aug. 26, 2026, in Bitcoin block 964,199. The associated GPU computing cost has fallen from about $320 to about $50. The design uses hash-based computation to build the locking mechanism, but it still requires heavy computation for each transaction. Starknet also said moving assets into the scheme still relies on a traditional transaction that carries quantum risk. In addition, the transaction does not comply with Bitcoin Core’s default relay policy, and there is currently no supporting wallet, address format, or recovery process. StarkWare described QSB as an emergency research approach rather than a final answer. The company said a long-term fix would still require a soft fork to introduce post-quantum signature mechanisms. It also noted that full quantum resistance for Starknet depends on the progress of upgrades at Ethereum’s base layer.
