Top Cryptographers Disagree on Bitcoin's Quantum Risk Significance Issue, But Recommend Immediate Initiation of Post-Quantum Signature Planning

June 13: The Cryptography Advisory Council, convened by Coinbase, has stated that quantum computers don’t pose an immediate threat to blockchains—but the Bitcoin community should immediately begin planning for post-quantum signatures. Council members include top cryptography experts like Scott Aaronson of the University of Texas at Austin, Stanford’s Dan Boneh, and Justin Drake of the Ethereum Foundation. The report identifies that Bitcoin’s quantum risk is concentrated in early addresses: around 1.7 million BTC are held in roughly 20,000 early public key addresses, where owners’ public keys are publicly posted on-chain, leaving them vulnerable to future quantum attacks. Many of these addresses are believed to belong to Bitcoin’s anonymous creator Satoshi Nakamoto or holders who lost their private keys, so their funds can’t be moved proactively to more secure wallets. Project11’s research adds that another ~5 million BTC face potential risk from address reuse, though most of these are active holdings in exchange wallets. The real debate isn’t about transitioning to post-quantum signatures—it’s how to handle unmigrated tokens. One side supports a hard deadline after which Bitcoin’s current ECDSA and Schnorr signatures will no longer be accepted, rendering unmigrated tokens unspendable. This aims to stop attackers from amassing large BTC holdings via future quantum hacks, which would hurt prices and the network’s legitimacy. The other side argues this is asset forfeiture, violating Bitcoin’s core principle of absolute property rights and setting a precedent for freezing tokens under government pressure. The council is taking no stance on the “abandoned tokens” issue, noting there’s no single correct answer—it’s up to the Bitcoin community to decide. However, the council emphasizes that technical migration planning should start right away: engineering work for post-quantum signature support is separate from governance disputes, so it shouldn’t wait for those fights to resolve. Clear communication is essential to keep users in the loop, as uncertainty around this issue is itself a risk.