Jiuzhang 4.0 Revives Debate Over Bitcoin’s Future Security

Quantum computing may have just entered a new era. China claims to have developed a machine capable of performing in 25 microseconds operations that no classical supercomputer could replicate before a time beyond comprehension. Behind Jiuzhang 4.0, presented by the University of Science and Technology of China (USTC), an explosive issue is already emerging for the crypto industry: the future security of bitcoin in the face of accelerating quantum technologies. This breakthrough also reignites the strategic battle between Beijing and Washington in the global race for computing power.

Jiuzhang 4.0 shatters the limits of classical computing

USTC officially unveiled Jiuzhang 4.0, a new version of its photonic quantum computer capable of manipulating 3,050 photons, compared to 255 for Jiuzhang 3.0 presented in 2023.

Professor Lu Chaoyang states that “the most complex data sample generated by Jiuzhang 4.0 requires only 25 microseconds, less time than a simple blink of an eye”. According to him, “a classical supercomputer would take more than 10 to the power of 42 years to produce the same result”.

Chinese researchers highlight several major technical advances :

• Manipulation of 3,050 photons compared to 255 for the previous generation ;
• Source efficiency increased to 92 % ;
• Overall efficiency reaching 51 % ;
• Optimization of the photonic interferometer ;
• A major breakthrough in the field of Boson sampling.

This photonic architecture differs from the superconducting approaches used by IBM or Google. USTC researchers also believe Jiuzhang 4.0 could pave the way to “trillion-qubit-mode three-dimensional cluster states”, a prospect described as a key step in the future development of quantum computing.

Bitcoin facing increasing quantum pressure

The Chinese announcement immediately rekindles concerns about bitcoin’s cryptographic security. Several ecosystem players now closely monitor the progress of quantum machines capable, eventually, of attacking the elliptic encryption systems used to secure BTC wallets. Discussions around the BIP-360 project, aimed at strengthening Bitcoin protocol’s quantum resistance, thus come to the forefront again as hardware advances accelerate.

An IBM system has managed to break a 15-bit ECC key, a demonstration admittedly limited, but enough to fuel debates on the future vulnerability of blockchain infrastructures. For some Bitcoin developers, the threat remains distant given current technical constraints. Others believe instead that the ecosystem must already prepare a gradual migration to post-quantum cryptographic standards before machine capabilities become truly exploitable at large scale.

This new Chinese demonstration thus goes beyond the simple scientific framework. It illustrates the rise of a technological competition where computing power becomes a matter of sovereignty, cybersecurity, and industrial dominance. For bitcoin and the entire crypto sector, the question is no longer just whether quantum computing will progress, but how fast current infrastructures must evolve to remain secure against this new generation of machines. But, some experts think it is already too late to migrate bitcoin.