Bitcoin Core developer Cory Fields proposed "quantum landmines" to discourage theft from wallets that quantum computers could one day crack. The idea would make attackers post matching collateral and risk losing it. Fields calls the ideas thought experiments, and they would need new consensus rules.
Bitcoin Core developer Cory Fields has proposed "quantum landmines", a system that could make future attackers risk their own Bitcoin when they try to steal from wallets vulnerable to quantum computers. He published the idea in a November 4 post on the Bitcoin Development Mailing List.
No such mechanism currently operates on Bitcoin.
Attackers would have to post matching collateral
The proposal targets wallets whose public keys have already appeared on the blockchain. A sufficiently powerful quantum computer could theoretically use an exposed public key to calculate the corresponding private key, though no publicly demonstrated quantum computer can currently carry out such an attack.
Under Fields' design, anyone spending these coins would supply collateral equal to the amount moved. In his example, moving 1 BTC would require another 1 BTC held in a quantum-safe wallet. Both amounts would enter a new output with spending restrictions, including a possible 30-day waiting period.
An owner who prepared a hidden ownership commitment beforehand could reveal it during that window. The owner could then reclaim the funds and take the attacker's collateral. Because the attacker would not know whether a wallet holds such a commitment, Fields suggested the uncertainty could discourage theft.
Auctions would cover wallets with lost keys
However, the landmine only works if owners still control their keys. Many older wallets may not meet that condition, since some owners have lost their private keys.
For those cases, Fields outlined a separate system of hidden bids against vulnerable holdings. In one example, a participant could prepare a bid against a dormant wallet containing 50 BTC. If an attacker later tried to spend the coins, an auction would begin after the initial ownership-proof period expired.
Neither auction design guarantees recovery for the original owner. Their purpose is to make theft less attractive by forcing attackers to risk their own funds.
Open questions and costs for legitimate holders
The collateral requirement could also burden people who legitimately own vulnerable coins. A holder whose entire balance sits in an older wallet might struggle to move it without obtaining additional Bitcoin.
Fields acknowledged that Bitcoin cannot automatically distinguish an owner from an attacker who recovered the same key. According to Fields: "The purpose of this post is just to introduce the ideas as thought experiments," he wrote.
Any implementation would first require quantum-safe transaction outputs and new consensus rules. The discussion also leaves collateral ratios, auction deadlines and penalties for losing bids unresolved.
Source: crypto.news
Trading involves risk.
Risk Disclaimer
