Crypto’s First Quantum Attack Could Appear as an Unexplained Breach: Quantus Founder

Crypto executives say malicious actors with access to a cryptography-breaking quantum computer are unlikely to reveal their capabilities by targeting Satoshi Nakamoto’s high-profile Bitcoin wallets.

The first indication that quantum computing has cracked modern cryptography is unlikely to come from a high-profile theft of Satoshi Nakamoto’s dormant Bitcoin. Instead, it could appear as a wave of seemingly unrelated crypto wallet breaches with no clear evidence of how the attackers gained access, according to the founder of blockchain startup Quantus.

“When someone breaks your key, you don’t receive a notice explaining how it happened,” Christopher Smith, CEO and co-founder of Quantus Network, told. A sufficiently advanced quantum computer could derive private keys from public keys exposed onchain, enabling attackers to move funds without breaching a wallet, device or exchange’s internal infrastructure.

This makes the arrival of “Q-day” — the hypothetical point when quantum computers become powerful enough to break standard public-key cryptography — particularly difficult to identify. In a theft targeting a highly secure organization, “the only forensic evidence would be that there was no breach,” Smith said.

Smith’s warning comes as progress in quantum algorithms has lowered estimates for the computing power required to attack the elliptic-curve cryptography that major blockchains rely on.

Satoshi’s Bitcoin May Not Be the First Target of a Quantum Attack#

Concerns surrounding Q-day in the crypto industry largely focus on the possibility that a quantum computer could break the cryptographic keys protecting Satoshi Nakamoto’s Bitcoin holdings, valued at about $63 billion at the time of writing, potentially allowing the coins to be sold into the market.

However, Smith said military systems and state secrets could become the first targets, while attackers targeting crypto may instead pursue even more valuable cryptographic keys.

“If I’m targeting blockchain systems, what is the most valuable single key? It’s probably Tether’s minting key,” Smith said. A quantum-enabled attacker could use an administrative wallet to create tokens out of thin air and sell them on the market before the issuer has time to respond, he added.

USDT operates across multiple blockchain networks, with some of those ecosystems already working actively on post-quantum migration efforts.

Another possibility is that attackers could begin with a more subtle opening move.

Sean Cheetham, a security researcher at Blockchain Capital, said an attacker would more likely target exchange hot wallets that “aren’t going to ring alarm bells” instead of attempting to steal Satoshi’s coins.

Smith said attackers could disguise a quantum-enabled theft as a routine security compromise.

“There’s an alternative scenario where they… have these plausible, deniable [explanations]: ‘Oh, somebody just lost their keys somehow,’” he said.

Quantum “Q-Day” Timeline Remains Difficult to Predict#

In March, Google brought forward its post-quantum migration target to 2029 after an AI-assisted breakthrough indicated that elliptic curve cryptography could be cracked using far fewer physical qubits than previously expected.

NGRAVE CEO Roy Blackstone said earlier quantum computing forecasts had failed to account for the parallel advances being made in artificial intelligence.

“Most threat models assumed we had well into the next decade before quantum technology could realistically crack the cryptography securing public keys, but it did not account for how fast AI would develop alongside it.”

Despite the growing urgency, experts remain divided over when quantum computers capable of breaking modern cryptography will become viable.

Smith, whose company is developing a blockchain network designed to be quantum-resistant from launch, said there was a “50-50” chance of that happening by 2028. He argued that ongoing AI-assisted advances in quantum algorithms and hardware research are making such predictions increasingly difficult to rely on.

Cheetham said the early 2030s “definitely is almost a certainty,” while an earlier breakthrough remains “more of a trailing probability.”

Michael Coates, the Solana Foundation’s chief information security officer, declined to provide a timeline in an earlier interview, saying that “there’s no way to know.”

“If you talk to people in the industry, they always say it is five years away, and that has been the case for more than a decade. Perhaps today they would say it is four years away,” he said. However, he added that the uncertainty should not justify delaying preparations

“Fortunately, blockchain networks are already moving toward post-quantum signatures rather than waiting for the threat to emerge,” Blackstone said. “If they failed to prepare, the consequences could be catastrophic.”