Blockstream CEO Adam Back publicly rebuked Castle Island Ventures partner Nic Carter after Carter explained why his firm backed Project Eleven, a startup that says it will protect bitcoin and other crypto assets from quantum computing risks. Back told Carter on X that his posts made “uninformed noise” and that they were “not helping.” The exchange highlighted a sharper split in the Bitcoin community over how loudly to warn about future threats. Back Calls Out Public Warnings According to Back, Bitcoin developers are not ignoring quantum risks; the work is happening quietly. He argued the technology is still “ridiculously early” and predicted no real threat for a few decades. Based on reports, Back welcomed the idea of being “quantum ready” while urging calm in public messaging, saying loud alarms can cause confusion rather than useful action. 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 Carter pushed back, saying he had been “quantum pilled” after conversations with Project Eleven CEO Alex Pruden and that he invested because he became deeply concerned. Carter also pointed out that he disclosed his financial stake in a Substack post on Oct. 20, and he accused some developers of being in “total denial.” He warned that governments are planning for a post-quantum era and called Bitcoin itself a tempting “bug bounty” if the cryptography is left unchanged. after, obviously, because we wouldn’t have made the investment if we didn’t think quantum was a risk. — nic carter (@nic_carter) December 19, 2025 Experts Divided On Timing Capriole Investments founder Charles Edwards told followers that a quantum threat could show up in as little as two to nine years unless networks move to quantum-resistant cryptography. According to public statements from Ethereum co-founder Vitalik Buterin, forecasting models place roughly a 20% chance that machines able to break today’s public-key cryptography could arrive before 2030, with a median projection nearer 2040. Vitalik has said no such machines exist today but has urged early preparation because migrating a global system takes years. Metaculus’s median date for when quantum computers will break modern cryptography is 2040: https://t.co/Li8ni8A9Ox Seemingly about a 20% chance it will be before end of 2030. — vitalik.eth (@VitalikButerin) August 27, 2025 Other voices are less alarmed. Multimillionaire investor Kevin O’Leary said he doubts breaking Bitcoin with quantum computing would be the best use of the technology, arguing it would deliver more value in fields like medical research. Such comments show how views vary not only on timing but also on the practical incentives behind a quantum attack. Research, Migration, And Market Signals Technical specialists point out one clear fact: there is currently no quantum computer capable of breaking Bitcoin’s cryptography. That fact has not stopped investors from placing bets on startups that claim to build protective tools. Castle Island’s investment, which resurfaced on social media recently, spurred fresh debate about transparency and whether public warnings help or harm the ecosystem. Featured image from Quartz, chart from TradingView
