#quantumsecured

A Quantum Advancement for AI Data Centres: Chinese Researchers Reveal Quantum-Secured Terabit Optical Architecture

Quantum-Secured Optical Interconnects

China's Hubei Optical Fundamental Research Centre developed and demonstrated a quantum-secured connection architecture to suit AI's high expectations. This represents a significant advancement for global data infrastructure. Data may move at terabit-per-second speeds thanks to this innovative system, which blends quantum cryptography and contemporary photonics to offer robust, long-term security and minimal power consumption.

AI has advanced at an unprecedented rate due to large language models (LLMs) and real-time processing for applications like autonomous cars, which have created previously unheard-of demands for incredibly high data. In addition, the infrastructure must contend with the rapidly rising electricity costs and the threat of quantum security, which might undermine existing encryption methods.

Data centres need to offer quicker and more reliable connections as a result of these issues. The creation of an all-optical transmission technique that lowers the power consumption of power-hungry digital signal processing (DSP) is the primary breakthrough in their study, the researchers noted.

Optical Innovation for Efficiency

The Chinese team focused on optimising traditional data transfer to satisfy the rigorous speed and energy efficiency requirements of modern AI data centres. They implemented the Self-Homodyne Coherent (SHC) transmission technique.

Traditional high-speed systems sometimes need complex and computationally demanding DSP to recover the local reference light needed for coherent detection. The SHC transmission approach, which employs the transmitter to deliver a low-power reference signal in addition to the high-speed data stream, greatly simplifies this process. This co-transmitted reference signal can then be used by the receiver to decode and process the incoming data.

This ingenious method offers several significant advantages. First, by reducing the need for complicated, energy-intensive DSP, it drastically reduces the complexity and power consumption at the receiving end. Second, it maintains high sensitivity and stability in signal detection for error-free data transfer. The design's ability to send data at speeds faster than 1.6 terabit per second was successfully demonstrated. The solution ensures minimal operating costs while making the transmission process largely all-optical and incredibly robust to address the energy problem that is prevalent in expanding data centres.

Quantum Cryptography for Security That Will Last

The security threat is as pressing. Public-key encryption methods such as RSA and ECC may become vulnerable due to the possible emergence of fault-tolerant quantum computers. To solve this problem right away, the Hubei design fully incorporates Quantum Key Distribution (QKD).

QKD creates secret encryption keys using ideas from quantum mechanics. The "no-cloning theorem," which maintains that an unknown quantum state cannot be accurately reproduced and so conforms with the fundamental laws of physics, is the foundation of this security. Because of this physical limitation, any attempt by an unauthorised third party (an eavesdropper) to measure or intercept the quantum-generated key bits will inevitably affect the quantum states, alerting the authorised users to a security breach.

Using the keys generated by QKD, this system enhances and secures AES-256 encrypted classical data connections. This combination ensures strong, long-term protection for sensitive data, even in the face of the threat posed by future quantum computing.

Signal Harmonisation Using Multicore Fibre

A major engineering problem is to ensure that extremely sensitive quantum signals and ultra-high-speed classical data may travel along the same physical infrastructure without interfering. Multicore fibres (MCFs) were employed by the researchers to address this issue.

Unlike traditional single-strand optical fibres, multicore fibres comprise several different optical channels within a single fibre cladding. This physical isolation enables the high-speed classical data signals transmitted over the efficient SHC system to carry the sensitive quantum signals required for QKD. This design successfully prevents cross-talk, or signal corruption, which would otherwise be a major issue.

Crucially, MCFs maintain full compatibility with the vast, existing global fiber-optic infrastructure, enabling data centre operators to enhance security without incurring costly renovations.

Thorough Verification and Field Experiments

The system's viability was thoroughly tested in both laboratory and field environments. While classical data was transmitted utilising the SHC system in controlled lab experiments using a seven-core cable, quantum signals were protected through QKD. This arrangement successfully allowed encrypted data transfer rates of 400 Gbit/s per fibre core. During these testing, the system achieved an impressive average Secret Key Rate (SKR) of 229 kbit/s, showing that enough secure keys were being generated to protect the rapid data flow.

The final validation was conducted over a 3.5-kilometer fibre length that was specifically designed to replicate the continual needs of a real data centre over the course of a 24-hour continuous trial. The network ran at a total of 2 Tbit/s (2,000 Gbit/s) of classical data during the trial period. The QKD system produced around 583 secure encryption keys per second, with an average SKR of 205 kbit/s while sustaining this throughput.

Using 1,440 session keys, the system successfully encrypted and decrypted an astounding 21.6 petabits of classical data in real time during the trial. This system is extremely reliable and efficient, as seen by its stability and low gearbox losses during this run, in addition to being ultrahigh-capacity and safe.

Opening the Path for Safe AI Development

These days, quantum-secured optical interconnects are seen as an essential and practical way to build the next generation of digital infrastructure. According to the researchers, their work "paves the way for the next generation of secure, scalable, and cost-efficient optical interconnects, meeting the high demands of modern data-driven applications while protecting AI-driven data centres against quantum security threats."

The Hubei Optical Fundamental Research Centre has successfully overcome the speed, power, and security constraints of existing systems by fusing cutting-edge photonics technology with the essential security of quantum encryption.