Intro to QuantumCTek Quantum Communication: How Keys Are Distributed and How Devices Connect

Forum topic · 小凯 · 2026-10-31

Summary

Quantum communication (specifically Quantum Key Distribution, or QKD) addresses a core security problem: sharing an encryption key between two parties while detecting any eavesdropping. QKD does not transmit files themselves; instead it uses faint optical signals, such as single photons, to negotiate random keys whose quantum states reveal interception attempts, while actual traffic remains encrypted with conventional symmetric algorithms. This article introduces QuantumCTek (Sino-USTC Quantum, stock-listed on the STAR Market), whose product line spans three layers: quantum key generation terminals (e.g., QKD-POL40, QKD-POL1250, QKD-PHA300), key management appliances, and encryption application devices including the SJJ1411 quantum cryptographic machine (950 Mbps throughput, 10 μs latency), quantum-safe IPSec VPN (SJJ1529, 1.6 Gbps filtering bandwidth, up to 3,500 tunnels), EQR-series encrypted routers, and quantum-safe firewalls. It also covers metro network deployments covering roughly 50 km per link and backbone networks supporting 100 km+ links, including the Beijing–Shanghai backbone line, serving government, finance, power, and telecom sectors.

Imagine mailing a box containing an important contract. What you fear most is not that someone opens and reads it — it's that it gets opened without you ever knowing. Quantum communication tackles roughly this problem: two parties need to share an encryption key while also being able to detect any eavesdropping.

The formal name of this technology is Quantum Key Distribution (QKD). It does not "quantum teleport" files directly; instead, it uses very weak optical signals such as single photons to negotiate a string of random keys between two endpoints. If someone eavesdrops, the quantum states are disturbed, and the protocol can detect the anomaly. Once the keys are generated, the actual business traffic is still encrypted using everyday symmetric encryption algorithms.

What QuantumCTek Does in This Space

QuantumCTek Co., Ltd. (official site: quantum-info.com) has technical roots at the University of Science and Technology of China, was founded in 2009, and listed on the STAR Market in 2020. Per the company's official profile, its main business covers quantum communication, quantum computing, and quantum precision measurement. Its quantum communication products are used in wide-area networks such as the "Beijing–Shanghai backbone line" (Jing-Hu trunk), serving government, finance, power, and telecom industries.

Their communication products can be roughly grouped into three layers:

1. How keys are generated: quantum key generation terminals 2. How keys are stored and managed: key management appliances 3. How business systems use the keys: encryption machines, VPNs, routers, firewalls

Representative Products (models and specs from the official site)

Key generation side (product page /product/quantum/), based on the decoy-state BB84 protocol, includes:

QKD-POL40: polarization encoding, providing QKD capability
QKD-POL1250: high-speed polarization encoding; the official site states it integrates transmit/receive modules with operating frequencies up to the GHz range, targeting high-speed, long-distance scenarios
QKD-PHA300: time-phase encoding, targeting special channels such as power overhead cables, bridge-mounted cables, and rail-buried cables; the official site calls it the world's first commercially available time-phase product
QKDM-POL40: integrates key storage and management in addition to distribution

Application access side (security application product pages):

Quantum Key Distribution Network Cryptographic Machine (approved model SJJ1411): integrates a fiber QKD module with a high-speed encryption board; supports SM1 or AES128/192/256 algorithms. Official specs: key update frequency 1–1000 times/second (configurable), ciphertext throughput 950 Mbps, encryption latency 10 μs. Listed in the national commercial cryptography product catalog.
Quantum-safe IPSec VPN (approved model SJJ1529 IPSec VPN-Q): uses quantum keys as session keys. Official specs: key updates 100 times/second, secure filtering bandwidth 1.6 Gbps, up to 3,500 concurrent tunnels, ciphertext throughput 500 Mbps, encryption latency 300 μs.
Quantum-safe Encrypted Router EQR series (e.g., EQR1000-C2, EQR2000-G, EQR3000-8G): combines routing, switching, wireless, VPN, and quantum secure communication in one device; per the official site, usable for HQ–branch interconnection, industry network aggregation/access, enterprise cloud adoption, and mobile office.
Quantum-safe Firewall: uses quantum keys for access authentication and business protection; the official site lists multiple throughput and concurrency tiers, targeting mobile office, e-government, and mobile payment.

Metro and Backbone Networks

Standalone devices are not enough — networking by distance is also needed.

Metro networks (/solution/access/): a single link can cover roughly a 50 km radius in megacities; supports star, ring, and hybrid topologies; through wavelength planning, narrowband filtering, and power control, quantum channels can share fiber with classical communications. Per the official site, deployed in metro networks in Hefei, Jinan, Wuhan, Beijing, Shanghai, Guiyang, and more.
Backbone networks (/solution/overview/): stably support single links over 100 km; can share equipment rooms and ducts with classical optical communication; work with buried and aerial cables; include classical backup links so business can still run encrypted when the main link is interrupted. Per the official site, deployed in the "Beijing–Shanghai trunk" and "Wuhan–Hefei trunk," among others.

The case study pages also list public deployments such as a bank metro ring network, off-site encrypted data transfer, the Beijing–Shanghai trunk project, and the Hefei metro demonstration network. Who is using it is clear at a glance: finance, government, telecom operators, and power organizations with high key-management and compliance requirements.

The Takeaway

For the business side, quantum communication is not about replacing the entire network — it's about getting "where keys come from, how they're updated, and how they connect to encryption machines / VPNs / routers" right first. QuantumCTek's official site documents this chain from QKD terminals up to metro/backbone solutions, with models and commercial cryptography certification parameters that can be verified directly on its product pages.

*Note: This is an English translation of a Chinese forum post. Product names, models, and specifications are cited from the vendor's official website (quantum-info.com).*