The quantum clock is ticking: it's Bitcoin's problem, not Ethereum's
Key takeaways
- By Samir Tabar|Edited by Betsy Farber Jun 10, 2026, 4:07 p.m. 4 min read Make preferred on (Andriy Onufriyenko/Getty Images)If bitcoin and Ethereum had been invented on the same day, nobody would have heard of bitcoin.
- A sufficiently advanced quantum computer, operating with fewer than 500,000 physical qubits, could derive a bitcoin private key from its public key in roughly nine minutes.
- Why bitcoin is exposedBitcoin's security rests on elliptic curve digital signature algorithms.
The quantum clock is ticking: it's Bitcoin's problem, not Ethereum's A recent research note published by Citi analysts reached a conclusion about quantum risk that should give every institutional bitcoin holder pause, Tabar explains. By Samir Tabar|Edited by Betsy Farber Jun 10, 2026, 4:07 p.m. 4 min read Make preferred on (Andriy Onufriyenko/Getty Images)If bitcoin and Ethereum had been invented on the same day, nobody would have heard of bitcoin. I sold every bitcoin Bit Digital held and deployed the proceeds into Ethereum. I have built one of the largest corporate Ethereum treasury positions in the world and said, on the record, that we will never sell it. People have asked me to articulate the single strongest argument for that conviction. On March 30, 2026, that argument arrived. Last month, Citi confirmed it.
In a research note published on May 18, Citi analysts warned that quantum computing advances have shortened the timeline for practical attacks on digital assets, and reached a conclusion that should give every institutional bitcoin holder pause: bitcoin faces significantly greater quantum risk than Ethereum, and the gap between them comes down not just to technology but to governance.
That finding echoes the landmark paper released in late March by Google Quantum AI in collaboration with Stanford University and the Ethereum Foundation, which found that the computing resources required to break bitcoin's foundational cryptography are approximately 20 times lower than previously estimated. A sufficiently advanced quantum computer, operating with fewer than 500,000 physical qubits, could derive a bitcoin private key from its public key in roughly nine minutes. That machine does not exist today. But the window to act responsibly is narrowing faster than most institutions realize. When Google raises the alarm, and Citi confirms it in the same quarter, this is no longer a fringe concern. This is the silver bullet. And it points directly at bitcoin.