StarkWare Completes First Quantum-Resistant Bitcoin Transaction Without a Fork

StarkWare says it has successfully completed the first quantum-resistant Bitcoin transaction on the mainnet, demonstrating a way to protect BTC from future quantum-computing attacks without changing Bitcoin’s consensus rules.

The test moves StarkWare researcher Avihu Levy’s Quantum Safe Bitcoin (QSB) method from research into a working transaction. The development comes as Bitcoin has recently returned above $80,000, putting renewed attention on the network’s long-term security as well as its market performance.

How StarkWare’s Quantum-Safe Method Works

The method is designed to address a specific weakness that could emerge when a Bitcoin transaction sits in the mempool waiting for confirmation.

Levy’s approach uses signature grinding. Instead of accepting the first valid signature, the system generates millions of candidates until it finds one with a structure designed to avoid exposing vulnerable public-key information to a future quantum attacker.

StarkWare says the transaction uses hash-based protection rather than relying on Bitcoin’s existing elliptic-curve cryptography. The company says this can protect coins against an attacker equipped with a sufficiently capable quantum computer.

However, the process is far from practical for everyday Bitcoin transfers. Generating the transaction can require hours of computation, making it deliberately expensive.

The Transaction Bypassed Bitcoin’s Normal Mempool

There is another major limitation.

The QSB transaction uses a nonstandard format, meaning ordinary Bitcoin nodes would not relay it through the public mempool. Instead, StarkWare had to send the transaction directly to a miner willing to accept it.

MARA mined the transaction through its Slipstream service, allowing the experiment to reach the Bitcoin mainnet despite its unusual format. StarkWare says the transaction was completed without requiring a network fork.

This makes the achievement an important proof of concept, but not yet a replacement for a network-wide upgrade.

StarkWare Still Wants a Bitcoin Upgrade

Levy does not view the method as the final answer to Bitcoin’s quantum-security problem.

StarkWare CEO Eli Ben-Sasson also supports a protocol-level solution that would provide broader protection across the Bitcoin network. The company instead sees QSB as a potential safety measure while developers work toward a permanent upgrade.

That distinction is important. The experiment shows that Bitcoin can support a quantum-resistant transaction under its existing rules, but it does not make the entire network quantum-safe.

For now, the test gives Bitcoin developers another option to consider as quantum computing technology advances.

What Happens Next for Bitcoin?

The main question is whether Bitcoin can eventually adopt quantum-resistant protections at the protocol level without creating major disruption for existing holders and applications.

StarkWare’s experiment shows that a network fork is not necessarily the only way to protect individual holdings today. However, the high computational cost and the need to bypass the standard mempool make the current approach more of a lifeboat than a permanent solution.

For Bitcoin, the next step will be turning that proof of concept into a broader and practical security framework before quantum computing becomes a serious threat.