Fully Connected Network

The Solution

Fully Connected Networks (eQKDnet)

Fully connected quantum networks are essential for today’s multi-user telecommunication infrastructure. zerothird provides the only quantum communication system that enables many users to exchange quantum-secure keys with each other simultaneously within a defined area—for example, between ministries in a capital city. These networks deliver the highest level of physical security and efficiency, ensuring fast and reliable communication across multiple stakeholders.

At the core of this capability are zerothird’s entangled photon sources, which generate a continuous C-band spectrum. This spectrum can be subdivided into up to 100 wavelength channels through wavelength-division multiplexing, allowing entanglement to be flexibly distributed among any two partners in the network. With just one central source and one detection unit per user, the system scales efficiently to 12 participants today, while remaining ready for larger deployments.

This architecture enables a star-topology eQKD network, where adding users scales linearly with the number of participants (n systems for n users plus the source). In contrast, BB84-based systems are limited to point-to-point connections, requiring O(n²) links—for instance, 10 users would demand 45 separate systems—making them impractical for modern network topologies.

Example of a 18dB diameter 7-user network being upgraded to 8 users. Only minor hardware changes have to be carried out at the source Ψ (for allocation of additional wavelength channels), all other users only have to perform software updates to account for the additional connection. Note that in our star topology, every user shares one secret and private key with every other one, i.e. a key rate of 150 bit/s for the 7-user network

QKD SPECIFICATIONS

Protocol

BBM92 (entanglement based), discrete-variable (DV) QKD

Source intrinsic QBER

< 0.5%

QBER during operation

optimized for best overall network performance

Secure key rate

3 users 50 km from source – 400 bit/s
7 users 35km from source – 100 bit/s
10 users 15km from source – 120 bit/s

Entanglement routing

deterministic wavelength multiplexing within ITU grid (center: 1560nm)

Physical fiber architecture

Star topology (each user connects to source)

Key architecture

Fully connected network (mesh), each user shares pairwise entanglement with each other one

Quantum channels

dedicated dark fibers (provided by customer)

GENERAL SPECIFICATIONS

Power supply / consumption

230 V ± 5%; <6 kW (for 3 users)

Mechanical system

19’’ modular sub-rack systems
1x entangled photon pair source
1x detection unit with SNSPD per user
1x secure key generation hardware unit per user

Frequently Asked Questions

Why should quantum threats impact my compliance strategy?

Quantum computing poses a direct threat to current cryptographic protocols mandated by regulatory bodies. Compliance standards increasingly require quantum-resistant measures, making proactive quantum-readiness essential to avoid regulatory risk and financial penalties.

How does zerothird’s consulting service mitigate quantum risks?

Our consulting team assesses your existing infrastructure, identifies quantum vulnerabilities, and provides clear, actionable roadmaps. We help implement quantum-safe practices, ensuring your compliance strategy meets future regulatory and security demands.

Is quantum compliance relevant today, or is it a future issue?

Quantum compliance is a current issue because encrypted data intercepted today can be stored and decrypted by future quantum systems. Immediate action ensures current compliance and safeguards sensitive data against future decryption risks.

What industries benefit most from quantum compliance consulting?

Highly regulated sectors, including finance, healthcare, government, telecom, defense, and critical infrastructure, particularly benefit from quantum consulting, as they face significant compliance and operational risks from quantum threats.

What does a typical quantum compliance engagement include?

An engagement typically involves a quantum vulnerability assessment, regulatory impact analysis, development of a quantum-readiness strategy, detailed recommendations, implementation support, and ongoing risk management consulting tailored to your specific regulatory environment.

FULLY CONNECTED NETWORK (eQKDnet)