In brief - Bernstein says quantum computing poses a challenge to Bitcoin but represents a manageable long-term upgrade cycle. - Blockstream CEO Adam Back said current quantum hardware remains extremely limited and far from breaking Bitcoin cryptography. - Developers are already working on quantum-resistant cryptography as part of a future protocol transition. The race between quantum computers and Bitcoin’s cryptography has become a recurring theme in the cryptocurrency industry. But even as anxieties over Bitcoin’s “Q-day” grow, a new report from investment firm Bernstein says the outcome is unlikely to be catastrophic for the world’s largest cryptocurrency. Instead, the firm argues quantum computing should be treated as a long-term upgrade cycle for Bitcoin and the broader crypto industry rather than an existential threat to the network. “The risk is neither existential, nor novel, and also not limited to crypto,” Bernstein wrote, noting that quantum computing also posed a threat to everything from financial services, military, and healthcare. According to Bernstein, the highest threat from quantum computing is to the 1.7 million BTC, around $116.6 billion, in legacy wallets from the days when Satoshi Nakamoto was still active online. That’s because this stash of Bitcoin was stored in early address formats that expose public keys on the blockchain and could be targeted in a “harvest now, decrypt later” attack. For newer encryption protocols, chains, and crypto-linked real-world assets, the threat is limited to some unsafe practices that can be mitigated and managed, the firm said. Bernstein also emphasized that quantum computing won’t impact Bitcoin mining in the near future. “Bitcoin mining has no realistic risk from [quantum computers] based on Shor’s algorithm, as SHA encryption used in mining is quantum safe—several millions of years even after recent improvements, including Grover’s algorithm.” Blockstream CEO Adam Back, a Bitcoin pioneer, who was recently