QSB Could Save Legacy Bitcoin From Quantum Theft
A new paper by Avihu Mordechai Levy (StarkWare) describes Quantum-Safe Bitcoin (QSB), a way to spend legacy Bitcoin outputs that would stay secure even if an attacker had a cryptographically relevant quantum computer. It works inside today’s Bitcoin Script with no soft fork. Under the paper’s Shor-only threat model, its recommended configuration (Config A) achieves roughly 2^118 second-preimage resistance while fitting inside Bitcoin’s existing legacy script limits of 201 opcodes and under 10,000 bytes (§4.5, §2.2). The spender […]