Quantum computing threat to Bitcoin may arrive sooner than expected: report

A new quantum computing report has warned that the cryptocurrency industry may be running out of time to prepare for cryptographic attacks that could eventually threaten more than $2 trillion in digital assets.

According to “The State of Quantum” from Quantus, shared with crypto.news, recent breakthroughs in quantum hardware and error correction have compressed expectations around when cryptographically relevant quantum computers could emerge.

The report argued that the threat is no longer theoretical because the mathematical path for breaking elliptic curve cryptography, the system securing Bitcoin and most blockchains, has already been understood for decades.

Researchers behind the report pointed to a series of developments from Google, IBM, and Quantinuum between 2024 and 2026 that they said changed how experts view the timeline.

Among the most significant was Google Quantum AI’s March 2026 paper, which estimated that Shor’s algorithm could break the secp256k1 elliptic curve used by Bitcoin with fewer than 500,000 physical qubits under certain hardware assumptions.

While the report acknowledged that no existing machine can currently break Bitcoin encryption, it argued that the estimated resource requirements have dropped sharply within a short period.

Quantus said three research papers released within roughly a year reduced the projected quantum resources needed to attack elliptic curve cryptography by nearly an order of magnitude.

Quantum timelines and crypto exposure collide

At the same time, the report argued that cryptocurrencies face a problem traditional internet companies do not. Unlike centralized services that can quietly update encryption standards through software patches, blockchains expose public keys permanently on public ledgers, leaving millions of addresses visible for future attacks.

The report described this as a “harvest now, crack later” risk, where attackers could collect blockchain data today and wait for sufficiently powerful quantum systems to emerge later.

Another issue highlighted in the report involves lost Bitcoin wallets. Quantus estimated that between 2.3 million and 3.7 million Bitcoin are likely inaccessible because owners lost their keys, including coins believed to belong to Bitcoin creator Satoshi Nakamoto.

Since those wallets cannot migrate to quantum-resistant addresses, the report warned they could become permanent targets once quantum attacks become practical.

“The only practical solution is to set a hard deadline for account owners to migrate their tokens to quantum safe accounts, after which all tokens held in vulnerable accounts will be permanently frozen,” said Auryn Macmillan, co-founder of Gnosis Guild, in comments included in the report.

Elsewhere, the report argued that much of the technology industry has already started preparing for post-quantum cryptography. NIST finalized post-quantum encryption standards, including ML-DSA, ML-KEM, and SLH-DSA in August 2024, while companies such as Google, Signal, Apple, and Cloudflare have already begun deploying post-quantum protections with migration targets extending into 2029 and 2030.

Bitcoin migration debate gains urgency

Meanwhile, the report said the crypto industry remains divided over how to handle migration. Bitcoin’s transition was described as particularly difficult because of governance coordination, scaling concerns, and the challenge of replacing existing signature systems without introducing new vulnerabilities.

As previously reported by crypto.news, Dan Boneh, a Stanford cryptographer and co-author of Google Quantum AI’s March 2026 paper, recently warned that rushing Bitcoin into a post-quantum migration could create bigger dangers than the current threat itself.

In a May interview highlighted by Isabel Foxen Duke, Boneh warned that “a hasty transition to post quantum[…]is more likely to cause a catastrophic bug than we’ll be attacked by a quantum computer.”

Boneh nevertheless argued that preparation cannot be ignored. According to the interview, he supported a gradual migration toward post-quantum signatures and hybrid cryptographic systems rather than a sudden replacement of Bitcoin’s existing elliptic curve architecture.

Hardware limitations also remain a concern for wallet providers attempting to support larger post-quantum cryptographic schemes. Aaron Chen, CTO of Keystone, said in the report that algorithms such as ML-DSA-87 place significant strain on hardware wallets because of memory and computing constraints.

“For a hardware wallet, the device is typically MCU-based, which means its hardware resources are inherently limited,” Chen said in the report, adding that preserving user experience while supporting post-quantum standards introduces “additional challenges for hardware wallet development.”

Elsewhere in the report, Matt Swayne, chief content officer at Resonance, argued that the crypto industry may be underestimating how quickly the technology is advancing.

“We often hear about quantum hype, but we also have to be aware that the quantum industry is underselling its progress,” Swayne said.

Quantus concluded that migration delays could carry financial and political consequences once quantum capabilities become viable.

According to the report, preparing too early mainly creates operational inconvenience and larger transaction sizes, while preparing too late risks fund losses, institutional panic, and regulatory intervention after quantum attacks become possible.