Post-quantum cryptography can make Bitcoin signature sizes magnify by up to 125 times — a technical fact that is now sparking intense debate about how fast the network should operate.
Mow invites rush
Samson Mow, founder of Bitcoin Jan3, announced himself over the weekend with a pointed gesture warning: Moving too quickly on quantum security may make Bitcoin more vulnerable, not less.
His comments came after Coinbase CEO Brian Armstrong and the company’s chief security officer, Philip Martin, called on the industry to start acting now against… Quantum computing Threats.
Mow was pushed back forcefully. He said the rapid move to post-quantum cryptography risks opening new vulnerabilities — including a breakdown in consensus and a sharp decline in the number of transactions the network can handle simultaneously.
“Simply put: Make Bitcoin secure against quantum computers only to have it hacked by regular computers,” Mo wrote on X.
It’s been almost 10 years since the Blocksize Wars ended and Brian hasn’t changed at all.
He still carries the same complete lack of humility and understanding. Brian forms an opinion first, along with a specific course of action and time frame, rather than starting with… https://t.co/Ti7QV63e7P
-Samson Mao (@Excellion) April 4, 2026
A ghost from Bitcoin’s past
At the heart of his concerns is the block size – the maximum amount of transaction data that can be placed within a single block Bitcoin roadblock. Larger post-quantum signatures mean more data per transaction, which means fewer transactions per block, which means a slower, more congested network.
Former Bitcoin developer Jonas Schnelle put the numbers to it, and Mo cited them directly. The effects go beyond speed. Block size has been a flashpoint before.
BTCUSD trading at $68,731 on the 24-hour chart: TradingView
Between 2015 and 2017, a bitter community dispute over whether Bitcoin’s block size should be expanded tore apart the ecosystem and eventually led to a chain fork.
This battle has raised profound questions about decentralization, network security, and who really decides the direction of Bitcoin. Mao warns that the same battle may return, which he calls “Blocksize Wars 2.0.”
Image: Wccftech
Where Mao draws the line
Mao is not saying that quantum threats should be ignored. His argument is about timing, not priority. Research into potential solutions is already underway, he said, and this work must continue.
But quantum computers are capable of breaking Bitcoin EncryptionHe said we still have at least a decade or two to go. He added that rushing to resolve a threat that does not yet exist creates real risks today versus protecting against something hypothetical tomorrow.
The debate is gaining urgency as new research emerges Google The California Institute of Technology has raised new concerns about how quickly quantum computing might develop.
Armstrong and Martin cited these findings as reason enough to move the schedule up. Mao’s position: The cure may be worse than the disease, at least for now.
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