That estimate is consistent with recent hardware developments. Earlier this year, Google researchers revealed that breaking the elliptic-curve cryptography safeguarding top cryptocurrencies like bitcoin and ether would require fewer than 500,000 physical qubits, a 20-fold decline from previous estimates. That prompted several observers, including Google, to pull forward the so-called Q-Day deadline to 2029.
The White House, meanwhile, is aiming to develop a powerful quantum computer by 2028 and shift high-value assets and federal data to post-quantum cryptography by 2030. That sets the clock. It creates a sense of urgency, Zervigon said.
Consensus speed is the real risk factor
Zervigon isn't alone in pointing to slow governance, not cryptography, as crypto's weak point.
Deutsche Digital Assets framed it as a clear cut speed differential between TradFi and decentralized rails.
“The difference — and this is the honest answer to the 'Bitcoin is uniquely vulnerable' narrative — is governance speed,” the bank wrote on July 23.
It explained that an investment bank like JPMorgan does not need to get a go ahead from millions of pseudonymous global participants before upgrading its cryptographic infrastructure.
“It needs a board resolution, a budget, and a vendor. Large financial institutions can and will migrate to post-quantum standards faster, more quietly, and more predictably than a decentralised public blockchain. That is not an argument against Bitcoin. It is an argument for taking its governance process seriously,” Deutsche Digital Assets added.