The cryptocurrency community is embroiled in a heated debate over Bitcoin's vulnerability to future quantum computing attacks, sparked by a public confrontation between Charles Hoskinson, founder of Cardano, and Adam Back, CEO of Blockstream.
Hoskinson issued a stark warning in a detailed video address, stating that over 34% of all Bitcoin—approximately 8 million BTC—is at risk of being stolen by quantum computers as early as the 2030s. This vulnerability stems from "legacy coins" stored in old address formats, such as pay-to-public-key-hash, where the public key is exposed on the blockchain. This includes an estimated 1.1 million Bitcoin believed to belong to Satoshi Nakamoto.
Hoskinson specifically criticized the proposed Bitcoin Improvement Proposal BIP-361, which aims to migrate vulnerable funds to post-quantum addresses. He argued the proposal is fundamentally flawed, as it would require a contentious hard fork—a move Bitcoin's community has historically resisted. Furthermore, he stated the proposal's zero-knowledge proof recovery system would fail to protect the 1.7 million Bitcoin in legacy wallets that predate the BIP-39 seed standard introduced in 2013.
Blockstream's Adam Back countered these claims on social media platform X, labeling current criticisms as "financial fearmongering" driven by interests in tech companies and specialized altcoins. He asserted that post-quantum cryptography research for Bitcoin is progressing rapidly and downplayed the immediate risk, treating it as a "laboratory experiment."
The debate highlights a core tension between Bitcoin's conservative evolution and the need for disruptive solutions. Hoskinson pointed to the governance challenge, noting that blockchains like Cardano, Polkadot, and Tezos have on-chain mechanisms to vote on such upgrades, while Bitcoin does not. He concluded with a provocative scenario, suggesting that major institutional holders like BlackRock, MicroStrategy, and the U.S. government—with fiduciary duties to protect their assets—could ultimately force a hard fork to safeguard the network if the quantum threat materializes.
