Cryptocurrency's first quantum attack or vulnerability that will manifest itself as unexplained: Qu

The first sign that quantum computing has broken through modern cryptography may not be the shocking theft of Satoshi Nakamoto's sleeping bitcoin. The founder of blockchain startup Quantus said it may be just a wave of unrelated crypto wallet intrusions without any trace of how the attacker got it.

Christopher Smith, CEO and co-founder of Quantus Network, said: "When someone breaks your key, you don't get a memo explaining how they got it." A quantum computer powerful enough can derive private keys from exposed public keys on the chain, allowing attackers to move funds without having to breach wallets, devices or exchange systems. This makes the arrival of "Q-day"-the hypothetical future moment when quantum computers are powerful enough to crack standard public-key cryptography-extremely undetectable. Smith said that in theft cases involving high-security organizations,"the only evidence available is that there are no signs of intrusion."

Smith's warning comes as advances in quantum algorithms have reduced estimates of the computing resources needed to attack elliptic curve cryptography used in major blockchains.

The first target may not be Satoshi Nakamoto's Bitcoin

Many concerns about Q-day in the crypto world are that if quantum computers crack the key protecting the bitcoins held by Satoshi Nakamoto (worth approximately $63 billion as of this writing), those bitcoins could be suddenly sold into the market. However, Smith said the first targets could be military systems and state secrets, and cryptographic attackers could target more valuable keys.

Smith said: "If you focus on blockchain, what is the most valuable single key? It's probably Tether's casting key." He added that quantum attackers could mince tokens out of thin air from management wallets and sell them to the market before the issuer could respond.

USDT is a multi-chain stablecoin, and some of its deployed networks are already actively undergoing post-quantum migration work.

Another theory is that attackers will take a more low-key opening move. Sean Kitam, a security researcher at Blockchain Capital, said attackers are more likely to target hot wallets on exchanges."These will not trigger alarms, rather than steal Satoshi Nakamoto's coins."

Smith said attackers could disguise quantum theft as a normal intrusion. "There is also a possibility that they... have these seemingly reasonable, deniable explanations: 'Oh, it's just someone somehow lost the key,'"he said.

Q-day timeline is difficult to determine

In March, Google moved forward its subsequent quantum migration timetable to 2029 after an artificial intelligence-assisted breakthrough showed that elliptic curve cryptography can be cracked with much fewer physical qubits than previously predicted.

Roy Blackstone, CEO of NGRAVE, said previous quantum predictions failed to consider parallel development of artificial intelligence. "Most threat models assume that we will need to wait until the next decade for quantum technology to truly crack the cryptography that protects public keys, but they don't take into account the speed at which artificial intelligence is developing in tandem with it."

Despite the growing urgency, there is little consensus on when quantum computers capable of cracking modern cryptography will be ready.

Smith's company is developing a blockchain network that aims to be quantum-resistant from the beginning of its launch. He said the possibility of this happening by 2028 is "50 - 50", and believes that continued improvements in quantum algorithms and hardware research assisted by artificial intelligence make predictions increasingly unreliable.

Chetham said that the early 2030s are "almost certain" and that an earlier arrival is "more likely to be tail probability."

Michael Coates, chief information security officer of the Solana Foundation, declined to give an estimate in an earlier interview, saying it was "impossible to know." He said: "If you talk to people in the industry, they always say there are five years left, and this has been going on for ten years or more. Maybe now people will say there are still four years away." But he added that uncertainty was not a reason for delay.

Blackstone said: "Fortunately, the blockchain has not waited and has begun to migrate backward quantum signatures. If we don't do this, the consequences will be disastrous."