First quantum-resistant Bitcoin transaction successfully executed, StarkWare says

StarkWare announced today that it has completed the first quantum-resistant Bitcoin transaction.

This development counters the idea that a network fork is the only way to secure bitcoin holdings against quantum computing risks, the company said.

Avihu Levy, the head of StarkWare's applications division, has devised a method that adds an "extra lock" to protect holdings by using signature grinding to prevent use of public key data while transactions sit in the Bitcoin mempool.

A Bitcoin transaction is exposed to quantum attacks when it waits in the mempool before it is confirmed. During this brief window, it reveals the mathematical material that could give a future quantum computer an opportunity to forge a signature and steal the funds.

StarkWare says signature grinding closes that window by refusing to accept the first valid signature and instead brute-forcing millions of candidates until one has a shape that does not expose the public key material to quantum computers.

This method is deliberately expensive, and can take hours of computing to produce a single transaction, StarkWare added.

"There is a catch for now. Bitcoin's network only passes along transactions written in the standard formats it recognizes, and this one is unusual enough that ordinary nodes would simply ignore it," the company said. "So instead of going into the public queue, it had to be handed straight to a miner willing to accept it."

StarkWare added that MARA mined its transaction through the Slipstream service.

Lifeboats

Despite his discovery, Levy favors making Bitcoin quantum-safe through a protocol-level upgrade. This view is shared by StarkWare CEO Eli Ben-Sasson, who said Levy's method can assist the network until it implements a permanent fork.

"Avihu's breakthrough is important because it gives the psychological reassurance which we need and which the asset itself needs," Ben-Sasson said. "The important thing is that opportunities are seized. I've said before that crypto is behaving like passengers on the Titanic. What Avihu has illustrated is that there are lifeboats. That is not a reason to relax. It is a reason to build more of them, and to build them now."