Quantum Key Distribution

The Problem

Current Encryption Standards Have an Expiration Date.

Today’s encryption relies on algorithmic complexity—soon to be vulnerable to quantum computers. Data intercepted now may be stored and decrypted later, putting long-term confidentiality at risk. Even post-quantum algorithms offer only temporary protection.

zerothird’s entanglement-based QKD resolves this by distributing entangled photon pairs from a source that doesn’t need to be trusted or secured, allowing identical keys to be derived through correlated quantum measurements and enabling instant detection of interception. Your data stays permanently protected, regardless of computing or hardware advancements.

Securing, today and forever:

Long-Distance Links Up To 350km

See Specification

Securing, today and forever:

Quantum-Secured Interconnects for Data Centers

See Specification

Securing, today and forever:

Metropolitan Quantum Networks for Smart Cities

See Specification

Securing, today and forever:

Fully Connected Quantum Networks

Key Benefit

Scientifically Provable Quantum Security for Today and Tomorrow.

Our QKD systems leverage quantum entanglement, not mathematics, to create provably secure cryptographic keys based on the laws of nature. Instantly detect interception, eliminating quantum and classical threats permanently.

Technology

Optimized Quantum Security—How zerothird QKD Works.

zerothird’s QKD system distributes entangled photon pairs between endpoints, where superconducting detectors measure correlated states to derive identical keys—no key ever travels the network.

QBER during operation

optimized for max key rate

Long-Distance Links Up To 350km

OPTICAL SPECIFICATIONS

Protocol

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

Source intrinsic QBER

< 0.5%

Secure key rate

>100 x 256bit AES key per hour @ 300 km

Quantum channel

dedicated dark fiber (provided by customer)

Quantum channel length

system optimized for ~ 300 km

Central wavelength

1550 or 1560 nm, ITU channels (DWDM 100 GHz)

GENERAL SPECIFICATIONS.

Power supply / consumption

230V ± 5%; <4 kW

Mechanical system

19’’ modular sub-rack systems:
1x entangled photon pair source
2x detection units with SNSPD
2x secure key generation hardware units

Quantum-Secured Interconnects for Data Centers
& Metropolitan Quantum Networks for Smart Cities

OPTICAL SPECIFICATIONS.

Protocol

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

Source intrinsic QBER

< 0.5%

QBER during operation

optimized for max key rate

Secure key rate

120 kbit/s @ 10 km (2dB channel attenuation)
20 kbit/s @ 50 km (10dB channel attenuation)

Quantum channel

dedicated dark fiber pair (provided by customer)

Quantum channel length

system optimized for ~ 10-100km

Central wavelength

1560nm, ITU channels (DWDM 100GHz)

GENERAL SPECIFICATIONS.

Power supply / consumption

230V ± 5%; <4kW

Mechanical system

19’’ modular sub-rack systems:
1x entangled photon pair source
2x detection unit with SNSPD
2x secure key generation hardware units

Frequently Asked Questions

What is entangled QKD, and why is it superior?

zerothird’s entangled QKD generates cryptographic keys from photon pairs whose quantum states are intrinsically linked (entangled). Unlike traditional encryption, any interception attempt disturbs the quantum correlations, which can be detected during key generation. This effectively provides a level of security not achievable by classical or algorithm-based methods.

What is the difference between Long-Distance and Metropolitan QKD systems?

Long-distance QKD secures transmissions up to 350km while minimizing reliance on intermediate (trusted) nodes, ideal for intercity links. Metropolitan QKD is optimized for shorter, densely interconnected networks, typically within city-wide infrastructures, such as data centers or campuses, ensuring high-speed, quantum-secure communication.

How does zerothird’s fully connected network QKD system work?

No. zerothird’s QKD solutions integrate seamlessly with existing standard telecom optical fiber and DWDM infrastructure, allowing immediate deployment without expensive infrastructure upgrades or significant downtime.

Why should we act now if large-scale quantum computers are still years away?

Sensitive data intercepted today can be stored and decrypted later using future quantum computers, a threat known as “harvest now, decrypt later.” With classical computing power also increasing rapidly through AI and specialized hardware, the risk horizon is accelerating. zerothird’s QKD solutions provide forward-secure protection now, eliminating the long-term vulnerability of today’s communications.

What does the QKD deployment process involve?

zerothird handles the end-to-end delivery, setup, and integration of QKD systems into your network environment. We work closely with your team to minimize disruption, adapt to your infrastructure, and ensure a smooth transition to quantum-secure communication.

Discover the Full Spectrum of Quantum Solutions.

Key as a Service.

Receive quantum-generated cryptographic keys directly to your endpoints—fully operated and maintained by zerothird, shifting QKD cost from Capex to Opex.

Product photo of zerothird S11 photon source

Quantum Equipment for Advanced Research.

Industry-leading photon sources and quantum measurement tools for lab-based quantum experiments.

Unbreakable Quantum Key Distribution at Scale.