A Bitcoin researcher has come up with a method that can instantly make Bitcoin transactions quantum unthreatening, without the need for a pliable fork.
In a proposal published on Thursday, StarkWare chief product officer Avihu Levy proposed a Quantum Safe Bitcoin (QSB) transaction scheme that he says he said it will remain unthreatening “even against an adversary equipped with a large-scale quantum computer running Shor’s algorithm.”
He added that the scheme does not require any changes to the Bitcoin protocol and works entirely within the existing constraints of the legacy script. The disadvantage is that it is steep and probably not useful for everyday transactions, he said.
The Bitcoin community is divided on how to solve the quantum problem. The QSB presents an interim solution until a long-term approach is developed.
The main feature of this scheme is to replace the proof-of-work signature-sized puzzle with a hash-to-sig puzzle.
Instead of relying on elliptic curve math that quantum computers can break, the person spending the money must find an input whose hash result randomly resembles a valid ECDSA (Elliptic Curve Digital Signature Algorithm) signature, requiring brute force that even a quantum computer cannot shorten.
Quantum Safe Bitcoin is not practical for everyday operate
However, the proposal contains reservations. It costs the sender between $75 and $150 per transaction in GPU calculations and is more sophisticated than a typical Bitcoin transaction, and therefore only makes sense for securing vast BTC transactions.
Related: Bitcoin’s quantum challenges are ‘more social than technical’: grayscale
“This is huge” he said StarkWare CEO Eli Ben-Sasson claiming that this essentially makes Bitcoin quantum unthreatening today.
However, Bitcoin ESG specialist Daniel Batten he said this was an “overkill” because exposed public keys and dormant wallets “were not addressed in the article.”
Batten was referring to the estimated 1.7 million BTC locked in early P2PK addresses that could be cracked by a quantum computer.
Its existence has led to fierce debate over what to do with dormant coins, with the community divided between leaving Bitcoin as is to preserve its core ethos, completely freezing or burning sensitive coins, or updating the protocol to support quantum-secure signatures.
Protocol changes are the preferred solution
Researchers admitted that this is a measure of last resort because the transactions are non-standard, the costs are not scalable to all users and they do not take into account operate cases such as Lightning Network.
They concluded that protocol-level changes remain the preferred long-term path.
“While this article describes a solution that works for quantum-secure Bitcoin transactions today, it should be considered as a last resort.”
In March, Google published a paper that alarmed the Bitcoin community because it suggested that a quantum computer could potentially crack Bitcoin’s cryptography using much smaller resources than previously thought.
Meanwhile, Lightning Labs Chief Technology Officer Olaoluwa Osuntokun on Wednesday published a prototype quantum “escape hatch” that allows users to prove ownership of a Bitcoin wallet based on the original seed phrase without revealing it, which could serve as an alternative method of Bitcoin authentication.
Warehouse: No one knows if quantum-secure cryptography will even work