China Telecom scores big in quantum sector

China has ushered in a new era of cybersecurity with the world's first commercially ready cryptography system that integrates quantum key distribution and post-quantum cryptography, marking a groundbreaking leap in defending against next-generation quantum computing threats.

In a landmark demonstration, China Telecom Quantum Group, which has developed the cryptography system, said it has successfully conducted a cross-province quantum-encrypted voice call spanning over 1,000 kilometers, showcasing the system's stability and real-world viability. This milestone underscores China's leadership in transitioning quantum-resistant technologies from labs to commercial applications.

Peng Chengzhi, chief quantum scientist at China Telecom Quantum Group, a unit of telecom carrier China Telecom, said the global development of quantum computing poses severe challenges to information security based on public-key cryptography, necessitating accelerated efforts to build new quantum-resistant information security infrastructure.

As a critical component of this infrastructure, quantum communication will play a foundational role in safeguarding national security by providing robust defenses against quantum computing threats, Peng said.

The move is part of China Telecom's broader push to develop quantum communication technologies.

The company said its quantum backbone now spans 16 cities including Hefei, Anhui province; Beijing; Shanghai; and Guangzhou, Guangdong province through metropolitan quantum networks, protecting government, finance, energy and other high-risk sectors.

China Telecom has also unveiled the Tianyan quantum computing cloud platform to demonstrate quantum computational advantages and the ability of quantum systems to solve problems beyond classical computers' reach.

The Tianyan platform runs an 880-qubit superconducting quantum computing cluster, which comprises one 24-qubit computer, two 176-qubit computers, and the Tianyan-504 superconducting quantum computer.

A classical computing bit can have a value of either 0 or 1, but a qubit can have a value that is either 0, 1 or a quantum superposition of 0 and 1. This gives quantum computers the ability to process some equations and algorithms exponentially faster than classical computers. The more qubits a quantum computer has, the more powerful it is, said Jia Zhilong, deputy director of the Anhui Quantum Computing Engineering Research Center's Quantum Computing Chip Provincial Key Laboratory.

Since its beta release, the Tianyan platform has garnered over 27 million global accesses, serving researchers and enterprises across more than 50 countries and regions. Users have submitted 1.4 million experimental tasks, China Telecom said.

According to the company, the Tianyan platform plans to connect to Zuchongzhi-3 — a superconducting quantum computer prototype developed by a team of Chinese quantum physicists that includes Pan Jianwei and Zhu Xiaobo.

Zuchongzhi-3 features 105 readable qubits and 182 couplers. It can process quantum random circuit sampling tasks at speeds a quadrillion times faster than the world's most powerful supercomputer, and 1 million times faster than results achieved by Google that were published in the journal Nature in October 2024, according to the team.