Overview
- StarkWare’s Quantum‑Safe Bitcoin (QSB) construction was mined on Aug. 26, 2026 as a nonstandard transaction submitted directly to a cooperating miner via MARA’s Slipstream service.
- QSB replaces elliptic‑curve signatures with hash‑based (Lamport‑style / RIPEMD‑160) authorization and uses signature grinding to find a valid spend without exposing a public key.
- Creating a QSB spend requires intensive off‑chain GPU work that current estimates put at roughly $75–$150 per transaction, with some runs costing a few hundred dollars and taking hours.
- The method is opt‑in and limited: it will not relay through ordinary mempools, it does not protect already‑exposed public keys, and it excludes Taproot outputs and Lightning channels, leaving an estimated ~7 million BTC still at risk.
- Next steps are independent reproduction, cryptographic review, wallet and mempool tooling, and a coordinated protocol‑level migration such as proposed BIPs or Blockstream’s SHRINCS if Bitcoin developers choose a network upgrade.