Samson Mow, founder of Jan3 and prominent Bitcoin advocate, has pushed back against calls for faster action on quantum computing defenses for Bitcoin. His comments came in response to statements from Coinbase CEO Brian Armstrong and chief security officer Philip Martin, who urged the industry to begin preparing for quantum threats sooner rather than later. Mow posted his response on X on Saturday, arguing that speed should not come at the cost of stability.
Mow acknowledged that post-quantum cryptography could protect Bitcoin against future quantum computers, but warned that a rushed transition carries its own dangers. These include compatibility issues and reduced network efficiency stemming from significantly larger signature sizes. In his view, moving too quickly could leave Bitcoin more exposed to present-day threats even before it addresses the quantum ones.
One of Mow’s central concerns involves the effect that post-quantum signatures would have on Bitcoin’s block size — the amount of transaction data that fits within a single block. Citing former Bitcoin developer Jonas Schnelli, Mow stated that post-quantum signatures could be ten to 125 times larger than current ones, which would substantially reduce transaction throughput. He warned this dynamic could trigger what he called “Blocksize Wars 2.0.”
Bitcoin’s original block size dispute began around 2015 and reached its peak in 2017, when the community became divided over whether to increase the block size to accommodate more transactions. That conflict raised fundamental questions about decentralization, network security, and governance of the protocol. It ultimately resulted in alternative scaling approaches rather than a straightforward increase to the block size limit.
The broader debate has been reignited by recent research from Google and Caltech, which renewed concerns about the pace of progress in quantum computing. These developments have prompted some industry figures to call for more urgent preparation across the cryptocurrency sector. Mow’s comments reflect a countervailing view that the timeline for a genuine quantum threat remains distant.
“Given that quantum computers don’t actually exist and likely won’t exist for another 10-20 years, the worst possible course of action is to rush a fix,” Mow said. He was careful to note, however, that ongoing preparatory work is both appropriate and already underway. His position is not that the issue should be ignored, but that implementation should not be accelerated beyond what careful development allows.
Originally reported by CoinTelegraph.
