Hoskinson Says Bitcoin’s BIP-361 Quantum Plan Could Leave 1.7M BTC Exposed

Highlights:

• Cardano’s founder said BIP-361 would still leave about 1.7 million Bitcoin exposed to quantum risk.
• He argued older wallets would not fit the recovery system discussed in the proposal.
• Hoskinson said the plan acts more like a hard fork than a soft fork.

Cardano founder Charles Hoskinson has raised new concerns about Bitcoin’s planned response to future quantum computing risks. In an X broadcast on Thursday, the Cardano founder said the current proposal may still leave many older Bitcoin holdings exposed.

He was referring to Bitcoin Improvement Proposal 361, or BIP-361. According to Hoskinson, the proposal would not fully protect coins tied to older wallet formats. He also said the fix may need much bigger changes to Bitcoin than supporters currently claim.

Charles Hoskinson: Bitcoin Quantum Fix Will Still Leave a Massive Chunk Of BTC Vulnerable@Cardano founder Charles Hoskinson (@IOHK_Charles) has publicly challenged Bitcoin's new quantum computing defense proposal, BIP-361, calling its recovery phase outright impossible.

The… pic.twitter.com/gkey6YJbLk

— BSCN (@BSCNews) April 17, 2026

BIP-361 proposes a step-by-step move to post-quantum security. First, Bitcoin would stop new transfers to addresses seen as vulnerable to quantum attacks. Then, after a long notice period, it would make older signature methods invalid. Later, a separate proposal may introduce a recovery option for some frozen coins.

BIP-361 Proposes Freezing Quantum-Vulnerable Bitcoin Addresses

Bitcoin developers and researchers have proposed BIP-361, which suggests freezing early Bitcoin addresses considered to have quantum vulnerabilities—primarily P2PK addresses with publicly exposed public keys—to… pic.twitter.com/C5zksSnW7l

— Wu Blockchain (@WuBlockchain) April 15, 2026

Hoskinson Questions Bitcoin’s Quantum Recovery Plan

Hoskinson said the proposal does not fully fix the problem. He argued that some exposed coins could still be moved or recovered, but about 1.7 million Bitcoin may remain at risk. Hoskinson tied that number to coins held in older wallets created before newer seed phrase standards became common. In his view, those holdings would not fit the zero-knowledge recovery model discussed in the broader plan.

Hoskinson also challenged the way supporters describe the proposal. He said the plan looks more like a hard fork than a soft fork. A soft fork tightens existing rules without fully breaking network compatibility. A hard fork makes broader changes that everyone on the network must follow.

He argued that the proposal forces older coins into a new security system and later removes support for legacy signature methods. In his view, that goes beyond the type of change BTC usually accepts through a soft fork.

That matters because Bitcoin has always been careful with major protocol changes. Hoskinson said this kind of move would be much harder to carry out because Bitcoin does not have formal onchain governance.

He compared Bitcoin with networks like Cardano, which already have governance tools built into the system. In his view, Bitcoin may eventually face a hard choice. It could approve a major and disruptive upgrade, or it could leave some vulnerable addresses exposed if quantum computing becomes a real threat over the next decade.

Old Coins Remain at the Center of the Concern

The most sensitive part of the debate involves very old Bitcoin, including coins many people believe belong to Satoshi Nakamoto. Hoskinson said some of these early coins cannot be recovered through the seed-phrase proof system discussed around the proposal. 

He stated: 

“So, so sorry, Satoshi. You just lost all your money. And they’re going to use the threat of a quantum computer to do it. Your alternative is to do nothing. And you’re just going to let the pirates take the gold. And you’re just going to have to endure 30% of the supply being dumped on the open market.”

Hoskinson ended by telling Bitcoin developers to go all the way if a big change is needed. He said they should use that moment to improve Bitcoin properly and bring in skilled people who can manage the work. “If you’re going to do a hard fork, do it right,” he said.

For now, the debate remains mostly theoretical because no quantum computer can break Bitcoin at scale yet. Even so, the discussion around BIP-361 shows the industry no longer sees this risk as pure science fiction.