Blockstream's co-founder Adam Back is advocating for an optional quantum-safe Bitcoin upgrade, arguing that a phased, gradual upgrade model with a longer migration window is more realistic than a mandatory global protocol change. This proposal offers a way for security-conscious users to enhance their assets against potential future quantum attacks while maintaining Bitcoin's conservative governance.
Adam Back's Proposal for Quantum-Safe Bitcoin
The proposal defines quantum hardening as voluntary participation rather than a forced fork. Users seeking protection can migrate early, while others can gradually follow suit over an extended timeframe until the old signature scheme is phased out.
The next day, Back stated that the level of support for changes typically correlates with their defensive value, believing that even those who think the quantum timeline is greatly exaggerated would support a long migration window.
“The demand for changes correlates with their defensive value. Therefore, I believe there will be reasonable support. Even those who think the quantum timeline is severely exaggerated are tired of panic-driven misinformation or understand the defensive value of a long migration window.”
Why Quantum Resistance is Now Part of Bitcoin's Roadmap
The same document clarifies the scope: P2MR can only defend against long-term exposure attacks, while short-term protection may require subsequent quantum post-signature proposals. This narrow framework makes the upgrade optional rather than a comprehensive cryptographic replacement.
Regulatory timelines are also tightening. BIP 360 mentions the migration deadlines for the U.S. CNSA 2.0, with software and network devices by 2030, and browsers and operating systems by 2033, noting that NIST IR 8547 plans to prohibit the U.S. federal government from using ECC after 2035, unless for mixed-use.
The Significance of Optional Upgrades for Bitcoin Users and the Network
For wallet holders and custodians, this template suggests how the rollout of the Bitcoin mainnet might operate: new address types coexisting with old ones, allowing users to choose when to migrate. Developers will need to take on a heavier task of integrating P2MR and any subsequent signature schemes into wallet software, hardware devices, and exchange withdrawal processes.
Additionally, Back mentioned that Taproot and Schnorr were designed with quantum transition in mind during 2018-2019, although unconfirmed reports from CoinEdition did not provide major technical statements supporting this design intent.
The next point of focus will be whether BIP 360 attracts further scrutiny from Bitcoin core contributors and whether more wallets and custodians will offer optional quantum post-address types according to the Liquid template before compliance pressures in 2030-2033.