Ethereum should not delay preparing for the threat of quantum computers, says Vitalik Buterin

Ethereum co-founder Vitalik Buterin is pushing the network to adopt cryptography that can withstand future quantum computing attacks now – before they become a problem. The prominent Ethereum figurehead warned that waiting until the threat is real could turn blockchain security into a race it can’t afford to lose.

In preparation for the day when a practical quantum computer comes online, Buterin argued in a post published Sunday on

“Ethereum, the blockchain, must have the properties we strive for in Ethereum applications,” Buterin wrote. “Therefore, Ethereum itself must pass the walk-away test.”

Even if development slows or stops, he says, Ethereum should remain stable, secure and reliable for decades to come.

A central part of his argument is the looming threat posed by quantum computing. Buterin said Ethereum should not wait to adopt cryptography that can withstand future quantum computers, even if current machines are not yet capable of breaking blockchain security.

“We must resist the trap of saying, ‘Let’s postpone quantum resistance until the last possible moment, in the name of pursuing greater efficiency for a while longer,’” Buterin said. He added that individual users have the right to delay making changes to prepare for a quantum threat, but protocols do not.

“Being able to say, ‘Ethereum’s protocol, as it stands now, is cryptographically secure for a hundred years’ is something we should strive to achieve as quickly as possible, and be proud of,” he said.

The post follows Buterin’s previous comments on the potential impact of quantum computing on blockchain security, but puts more emphasis on the risks of waiting. Buterin’s view on quantum risk has changed over the years since 2019, when he downplayed Google’s quantum advances. He now argues that systems like Ethereum cannot afford to treat quantum resistance as a last-minute upgrade once the technology becomes a reality.

Blockchains face particular scrutiny because networks like Bitcoin and Ethereum rely on elliptic curve cryptography. While it is safe for today’s computers, it can be broken by sufficiently powerful quantum machines that use Shor’s algorithm to extract private keys from public keys.

Although researchers say current quantum machines are still too small and unstable to threaten real blockchains, advances in hardware, error correction and system stability have refocused discussions about future timelines.

Despite Buterin’s call to action, others warn that making changes too quickly could have unintended consequences.

“Post-quantum crypto is often about 10 times slower, 10 times larger trial sizes, and 10 times more inefficient,” Charles Hoskinson, founder of Cardano and co-founder of Ethereum, told me. Declutter in a recent interview. “So when you adopt it, you’re essentially taking the throughput of your blockchain and reducing it by cutting off a zero.”

In addition to the walkaway test, Buterin outlined technical priorities he believes Ethereum must address to remain viable in the long term – including an architecture capable of scaling to thousands of transactions per second through mechanisms such as zero-knowledge EVM validation and data availability sampling, with future growth handled largely through parameter changes.

He also pointed out the need for sustainable state design, a general purpose accounting model that goes beyond ‘entrenched’ [Elliptic Curve Digital Signature Algorithm] signatures,” a gas program hardened against denial-of-service attacks, proof-of-stake economics that can remain decentralized in the future, and block building mechanisms designed to resist centralization and remain censorship-resistant.

Buterin said the goal is to complete this work in the coming years, arguing that future innovations should occur largely through customer optimization and limited parameter changes rather than repeated upgrades.

“Every year we need to check at least one of these boxes, and ideally several,” he wrote. “Do the right thing once, based on knowing what is truly right (and not compromising halfway), and maximize Ethereum’s technological and social robustness for the long term.”