Quantum attack breaks crypto key 512x larger than last record. Is Bitcoin ready?

Bitcoin’s timeline to deal with quantum computers just got a little bit shorter.

A researcher called Giancarlo Lelli performed the largest known quantum attack on elliptic curve cryptography, the standard that secures Bitcoin, Ethereum, and a vast majority of the $2.6 trillion crypto market. Lelli’s breakthrough is a 512-fold jump from the previous record.

Even though the result doesn’t break Bitcoin, it suggests something pretty unsettling. Progress towards breaking the $1.5 trillion network is accelerating on hardware that anyone can rent.

“The winning submission came from an independent researcher working on cloud-accessible hardware,” said Andy Pruden, CEO of Project Eleven, a startup dedicated to addressing Bitcoin’s quantum computing threat.

“The resource requirements for this type of attack keep dropping, and the barrier to running it in practice is dropping with them.”

What was considered a far-fetched threat not too long ago has now taken centre stage. In January, Wall Street behemoths like BlackRock and $5 trillion UBS CEO Sergio Ermotti denounced the quantum threat, while developers turned a blind eye. Not anymore. After Google accelerated its timeline for quantum to 2029, Bitcoin maintainers have begun to think about ways to stave off the threat.

Now there’s a proposal to freeze any quantum-exposed coins — including Satoshi Nakamoto’s purported 1.1 million stash.

6 bits to 15 bits

Lelli’s record shatters its predecessor by seven months.

In September 2025, Steve Tippeconnic broke a 6-bit cryptographic key on quantum hardware in what was considered the first public demonstration of its kind.

By using a cloud-accessible quantum computer, Lelli broke a 15-bit key. Project Eleven awarded him one Bitcoin for the breakthrough.

Bitcoin’s encryption algorithm uses 256-bit keys. That means the gap from 15 to 256 is enormous, but to have a researcher break the previous record by a multiple of 512, in less than a year, only highlights how exposed Bitcoin is.

Researchers at Chaincode Labs estimate up to 60% of Bitcoin's entire supply — roughly $800 billion — could be vulnerable.

Crisis on all fronts

There’s another, bigger, problem.

Every major US miner has begun migrating its infrastructure to AI as the sector got hot at the same time that Bitcoin mining became deeply unprofitable following the 2024 halving event, said Bernstein analysts.

To boot, network activity has plummeted since Bitcoin exchange-traded funds launched in January 2024, draining the very transaction fees that miners are increasingly relying on.

If quantum computing arrives while miners are abandoning the network, Bitcoin’s security could collapse quickly.

“Long story short, it’s not great,” Nick Hansen, CEO of mining outlet Luxor, previously told DL News. “There isn’t a bullish catalyst for continued investment in new mining right now.”

“I’m a six to seven on the worried scale.”

Pedro Solimano is a markets correspondent based in Buenos Aires. Got a tip? Email him at psolimano@dlnews.com.