In brief

• Charles Hoskinson said quantum-resistant cryptography is already standardized, but remains too slow for widespread use.
• He pointed to DARPA’s quantum benchmarking program as a key reference for when cryptographic risk becomes practical.
• Hoskinson said Cardano is exploring staged mitigations while waiting for hardware acceleration to mature.

As blockchain developers debate protocol updates to counter possible future quantum attacks, Cardano founder Charles Hoskinson said the central issue is timing and not what changes to make, warning that moving too soon could carry a high cost for blockchain networks.

According to Hoskinson, the cryptographic tools needed to protect blockchains from future quantum attacks already exist, pointing to post-quantum standards released by the U.S. National Institute of Standards and Technology in 2024. The problem Hoskinson explained is what it would cost if the new protocols are implemented before miners and validators are ready.

“Post-quantum crypto oftentimes it’s about 10 times slower, 10 times larger proof sizes, and 10 times more inefficient,” Hoskinson told Decrypt. “So if you adopt it, what you’re basically doing is taking the throughput of your blockchain and reducing it by cutting off a zero.”

While researchers broadly agree that sufficiently powerful quantum computers could one day break today’s cryptography, there is far less agreement on when that threat becomes real. Estimates place the arrival of a practical quantum computing anywhere from a few years to more than a decade away.

Hoskinson said instead of focusing on hype and corporate timelines when judging how quickly the threat might arrive, paying attention to DARPA’s Quantum Benchmarking Initiative, which is testing whether different quantum computing approaches can deliver useful results, would be a better option.

“It’s the best independent, objective benchmark that can be referenced for whether quantum computers are going to be real or not, and when they’re going to hit and who’s going to make them,” he said.

DARPA has set 2033 as a target year for determining whether utility-scale quantum computing is feasible.

Like most major networks, including Bitcoin, Ethereum, and , Cardano relies on elliptic-curve cryptography, which could theoretically be broken by Shor’s algorithm if sufficiently powerful quantum computers emerge. Hoskinson said the industry already knows how to address that vulnerability, but said the debate came down to a choice between two competing cryptographic approaches.