Quantum-Safe Bitcoin Transaction Mined on Live Network

A quantum-safe Bitcoin transaction has been mined on the live network for the first time. The transaction was made possible by StarkWare's Quantum-Safe Bitcoin (QSB) method, which uses signature grinding to produce a valid Bitcoin signature without a private key.

The QSB method attaches a hash-based lock beside the elliptic curve signature that normally guards a Bitcoin output. This makes it difficult for quantum computers to break the signature using Shor's algorithm.

According to StarkWare, this transaction does not make Bitcoin quantum-safe overall. There are three constraints that narrow what the QSB method actually protects: prior exposure, migration step, and delivery.

The cost of computing off-chain is estimated to be around $75 to $150, which may deter widespread adoption.