Quantum-Resistant Bitcoin Transaction Confirmed on Mainnet
A quantum-resistant Bitcoin transaction has been confirmed on the mainnet for the first time, demonstrating that the network can defend against future quantum attacks without changing its underlying rules. StarkWare says it achieved this milestone using a method called Quantum Safe Bitcoin (QSB), which works by rethinking how a Bitcoin signature is generated and relying on RIPEMD-160 hashing instead of elliptic-curve cryptography.
According to the company, QSB offers roughly 118-bit resistance against Shor's algorithm, a theoretical attack that could be mounted by a sufficiently powerful quantum machine. However, this protection only applies to individual transactions, not the entire network, and can only be used with older pre-SegWit addresses.
StarkWare emphasizes that QSB is not a long-term solution but rather a stopgap measure while they push for more comprehensive upgrades like BIP-360. The company's CEO, Eli Ben-Sasson, has likened the situation to passengers on the Titanic, noting that while proof of concept exists, more 'lifeboats' are needed to protect against potential threats.
For now, QSB is not available through mainstream wallets or exchanges and comes at a higher cost than standard Bitcoin transactions. While it demonstrates that Bitcoin's existing rules can accommodate quantum defense without triggering a network split, its limitations mean it is primarily of interest to custodians and developers looking for ways to enhance security.