Bitcoin Quantum-Safe Scheme Completes First Mainnet Transaction Without Soft Fork 

A Bitcoin mainnet transaction has been confirmed using an experimental security scheme that replaces reliance on elliptic-curve cryptography with hash-based assumptions, potentially defending against Shor-algorithm attacks without altering Bitcoin’s consensus rules.

StarkWare researcher Avihu Levy developed the Quantum-Safe Bitcoin (QSB) scheme. Its mainnet transaction shows the approach can operate without a Bitcoin soft fork.

QSB is designed to address the threat that sufficiently capable quantum computers using Shor’s algorithm could pose to elliptic-curve cryptography. 

The scheme remains experimental and carries a substantial computational cost. Each transaction currently requires off-chain GPU computation estimated at $75 to $150.

Source: STARKWARE