Quantum computing has long been a distant theoretical threat to blockchain cryptography. But that has changed rapidly in the past few months.
While the Bitcoin community has spent the past year debating threats to its protocol, the Ethereum community looks set to take the first step in 2026.
“Quantum computing is moving from theory to engineering,” said Thomas Coratger, head of the Post-Quantum (PQ) team at the Ethereum Foundation (EF). “That changes the timeline, which means we need to be prepared.”
In early January, EF officially promoted post-quantum security as a strategic priority and established a dedicated PQ team to drive research, tools and practical upgrades to protect the network’s cryptographic foundation.
Meanwhile, major industry players are building their own defenses: Coinbase announced the creation of an independent quantum advisory committee of leading cryptographers to guide long-term blockchain security planning, demonstrating that even custody infrastructure must be prepared for the risks of the quantum era.
Across the ecosystem, Optimism, one of Ethereum’s largest layer 2 networks, has laid out a formal 10-year roadmap to move its superchain stack from wallets to sequencers to post-quantum cryptography, working to phase out vulnerable signatures and ensure the continuity of the layer 2 network.
Taken together, these initiatives mark a significant shift: Post-quantum security is no longer a fringe topic in the distant future, but a real-time concern shaping development roadmaps, governance discussions, and ecosystem coordination across Ethereum and beyond.
For EF, the move towards post-quantum security is not about sounding alarm bells, but about avoiding being caught off guard.
Before officially announcing the work this month, Korag had been quietly working on post-quantum research within EF for the past year. The formation of the dedicated team exposes what was already a growing internal concern: If quantum computers arrive sooner than expected, Ethereum needs to be ready before that moment.
Currently, the team is focused on Ethereum’s “consensus layer” — the part of the network that enables thousands of validators to agree on which transactions are valid and which blocks are added to the chain. Today, the system relies on cryptography that currently works well but may eventually be broken by powerful quantum computers.
One of the biggest challenges is replacing Ethereum’s current signature system, which effectively bundles the approval of thousands of validators.
“The system is working really well today,” Korager said. “But post-quantum alternatives don’t have the same properties. Figuring out how to make them work at the scale of Ethereum is a significant challenge.”
To solve this problem, the foundation is building what it calls leanVM, a highly specialized piece of software designed to consolidate many post-quantum approvals into a single proof that can be added to the blockchain without overwhelming it. While the underlying technology is complex, the goal is simple: keep Ethereum running smoothly even if the underlying cryptography needs to change.
This work is already underway in practice.
“We already have test networks running post-quantum signatures,” Korag said.
Importantly, Korag emphasized that Ethereum is not in immediate danger. There is a gap between the speed at which technology is changing and the speed at which decentralized networks are evolving, which is why the Foundation is taking action now. The goal is to ensure the transition is completed before quantum computers become a real threat.
“The worst-case scenario is that quantum computers arrive and we’re not ready,” Korag said.
One of the things that’s stood out to Korag over the past year is how quickly basic science is advancing.
“New breakthroughs happen all the time,” he said. “It’s hard to keep up sometimes.”
To keep pace, the Ethereum Foundation is working closely with external researchers and developers on post-quantum research.
For Korateg, the bottom line is that post-quantum security has crossed an important threshold.
This is no longer a distant thought experiment or a purely academic debate. For Ethereum, it is becoming a long-term engineering project that will determine how the network evolves over time.
Read more: Ethereum Foundation makes post-quantum security a top priority as new team forms
