Samson Mow, founder of Jan3 and a vocal Bitcoin proponent, warned that hurried efforts to make Bitcoin quantum-resistant could create new vulnerabilities. His comments followed calls from Coinbase CEO Brian Armstrong and CSO Philip Martin for the industry to begin preparing sooner for threats posed by future quantum computers.
Mow said post-quantum (PQ) cryptography can protect Bitcoin from quantum attacks, but a rushed, network-wide rollout risks incompatibilities, much larger signatures and degraded performance. He summarized the danger bluntly: “Simply put: make Bitcoin safe against quantum computers just to get pwned by normal computers.” In his view, a poorly timed transition could weaken defenses against present-day threats while attempting to guard against a far-off risk.
The exchange revived a broader debate about how to future-proof Bitcoin. Recent research from Google and theoretical work from Caltech researchers have renewed attention on quantum progress and its implications for cryptography. A concrete technical concern is signature size: former Bitcoin developer Jonas Schnelli has estimated PQ signatures might be roughly 10–125 times larger than current ones. Such an increase would cut throughput, strain node and bandwidth resources, and could renew pressure to increase block size—a scenario Mow dubbed a potential “Blocksize Wars 2.0.”
Those earlier block-size disputes, which peaked between 2015 and 2017, revolved around scaling, decentralization and control over Bitcoin’s development path; the community ultimately pursued other scaling solutions rather than simply enlarging blocks. Mow said he opposes a rushed, network-wide PQ rollout but supports continued research and planning. He noted many experts project practical quantum computers are still 10–20 years away, so rushing a fix now could do more harm than good even as engineers and researchers continue assessing and designing appropriate solutions.