Quantum Threat to Bitcoin Decades Away, Says Blockstream CEO

Blockstream CEO Adam Back says quantum computers pose no immediate threat to Bitcoin's elliptic curve cryptography, describing the timeline for any real risk as decades away. He pointed to the limited capabilities of existing quantum hardware, noting that the largest calculation performed so far is factoring 21 into 7 times 3.

Back's team at Blockstream is already working on post-quantum approaches, with implementations contributed to Liquid, the Bitcoin layer-two network. In March, Back proposed bit 360, a pay-to-Merkle-root mechanism by developer hunterbeast, to address public key exposure risks in Taproot and legacy addresses. The National Institute of Standards and Technology approved post-quantum cryptography standards in late 2024, providing a framework for future upgrades.

Back also dismissed AI and artificial general intelligence as structural risks to Bitcoin. He characterized AI as a productivity tool that can assist researchers and engineers rather than compromise cryptographic systems. His broader vision for Bitcoin remains unchanged: he described it as digital gold that will coexist alongside national monetary systems rather than replace them.

Cryptographer Tim Ruffing's research supports Back's position. Ruffing demonstrated that Bitcoin's Taproot commitment scheme is already post-quantum secure, providing a built-in pathway to switch cryptography without losing funds. Back warned that rushing new cryptography into Bitcoin would be more dangerous than the quantum threat itself, advocating for phased upgrades that leverage Taproot's existing support through late 2024.