Adam Back, CEO of Blockstream, criticized Castle Island Ventures partner Nic Carter for exaggerating concerns about the threat quantum computers pose to Bitcoin.
Bitcoiners and developers are NOT in denial about defensively doing the r&d to prepare for future quantum computers. But they are just quietly doing research while you make uninformed noise and try to move the market or something. You’re not helping…
— Adam Back (@adam3us) December 19, 2025
According to the entrepreneur, developers of the first cryptocurrency acknowledge the issue and are conducting relevant research.
“But they are just quietly working while you make uninformed noise and try to influence the market or something like that. You’re not helping…,” Back stated.
Carter reiterated previously expressed concerns that many Bitcoiners ignore the quantum risk. He believes the potential threat is already putting pressure on the digital gold’s prices due to growing investor fears.
The community pointed out a conflict of interest, as Castle Island Ventures funded the startup Project 11, which is promoting tools to protect Bitcoin from the quantum threat.
FYI: Nic Carter’s fund is invested in a start-up that sells tooling to transition blockchains to quantum resistance. pic.twitter.com/lqvRwYpJyJ
— Pledditor (@Pledditor) December 19, 2025
Carter clarified that he disclosed information about supporting the project back in October, anticipating such accusations. He explained the investments by his personal conviction in the importance of solving the problem.
“I am extremely concerned about quantum threats to blockchains. I have always put my money where my beliefs are,” he added.
Back believes that computational systems capable of breaking Bitcoin’s cryptography will emerge no earlier than 20-40 years from now. However, he does not rule out that quantum technologies may never reach such capabilities.
Charles Edwards, founder of Capriole Investments, believes that the real threat of a breach will arise within two to nine years if the network does not implement protective mechanisms.
A quantum computer will break Bitcoin in just 2-9 years if we don’t upgrade. With high probability in the 4-5 years range. This is the timeframe all quantum experts converge on. Don’t believe the naysayers. We have already entered the Quantum Event Horizon: the frontier risk of a… pic.twitter.com/Alm939Ky7t
— Charles Edwards (@caprioleio) December 19, 2025
“With high probability, this will happen in four to five years. This is the timeframe all quantum technology experts converge on. Don’t believe the skeptics. […] We must act already in 2026,” he stated.
Some commentators questioned the consensus he claimed among specialists regarding the timeline. For instance, the University of Waterloo predicts that breaking RSA-2048 encryption using quantum computing will be possible by 2052.
As reported, the main threat to Bitcoin in this context lies in the consensus problem, not the technology, according to James Check, founder of the analytical service Checkonchain.