Overview
- Avihu Levy of StarkWare published the Quantum Safe Bitcoin (QSB) paper Thursday, proposing a way to send transactions that resist quantum attacks without changing Bitcoin’s rules.
- QSB swaps standard elliptic‑curve signatures for a hash‑to‑signature brute‑force puzzle, shifting security to hash preimage resistance and targeting roughly 118‑bit strength against a Shor‑style threat.
- Creating one QSB transaction requires billions of trials on GPUs, which Levy estimates would cost about $75 to $200 per send using commodity cloud hardware.
- The transactions are large and non‑standard, so they likely would not relay across the network under default policies and would need direct miner submission, and they do not work with the Lightning Network.
- Levy calls QSB a last‑resort tool for high‑value moves as a slower, scalable fix such as BIP‑360 advances, with critics warning it does not protect already exposed public keys or dormant legacy wallets even as recent Google research has raised urgency.