Quantum communications

Quantum-secure keys over the networks you already run.

Quantum key distribution for fibre and free-space links: CV-QKD on the fibre you already have, DV-QKD reception at the ground station.

Why now

Intercept today. Decrypt tomorrow.

Harvest now, decrypt later is already under way: encrypted traffic captured today and held until a quantum computer can break it. For data that must stay confidential for decades, the threat is not in the future.

Cryptography at risk RSA · ECC

The key exchange that protects most of today’s traffic is vulnerable to Shor’s algorithm at sufficient scale.

Secrecy lifetime 20+ years

State secrets, medical records and intellectual property must remain confidential beyond any plausible quantum horizon.

The physical answer QKD

Keys whose secrecy rests on physics and a security proof, not on the adversary’s computing power: to intercept is to disturb, and disturbance is detectable.

How it works

How light becomes a key

1

Quantum state transmission

The transmitter encodes random information in Gaussian-modulated coherent states of light and sends them over the quantum channel: fibre or free space.

2

Measurement

The receiver measures both quadratures of the incoming states by heterodyne coherent detection. A third party cannot measure without adding noise the receiver sees.

3

Classical post‑processing

Over an authenticated classical channel, both parties estimate the information leaked, then run error correction and privacy amplification.

4

Shared secret key

Secret under a composable security proof. Used to refresh AES-256 keys, or as a one-time pad (OTP) for low-rate data.

Fibre and free space

One principle, two channels.

Fibre · CV-QKD

QKD over the fibre you already have.

Our continuous-variable QKD (CV-QKD) systems run over standard single-mode fibre at 1550 nm, designed to share fibre with classical channels through dense wavelength-division multiplexing (DWDM).

TX RX QUANTUM CHANNEL · 1550 nm METROPOLITAN NETWORK
50 km of standard single-mode fibre (10 dB channel) demonstrated with distilled secret key.
Free space · DV-QKD

Bridging orbit and network.

Optical satellite-to-ground links are the scalable route to intercontinental QKD, with the satellite replacing long chains of ground relay nodes. We build the discrete-variable QKD (DV-QKD) reception hardware for optical ground stations (OGS).

SAT · LEO OGS
1.8 km urban free-space DV-QKD link in Madrid, demonstrated by our founding team at the Spanish National Research Council (CSIC) within the Madrid Quantum Network (EuroQCI).

Solutions

Hardware for both channels.

Q-Dynamics CV-QKD ALICE Tx transmitter unit, 19-inch 3U rack, with KMS, MGMT, SYNC and QKD interfaces ALICE Tx · BOB Rx · 19″ rack · 3U

CV-QKD system

ALICE Tx and BOB Rx units for point-to-point links over standard single-mode fibre, with a built-in Key Management System (KMS).

Q-Dynamics DEOM QKD demodulator, benchtop module with In, Out 0–3, Sync and Mon optical connectors DEOM · OGS Quantum Stack

OGS Quantum Stack

QKD demodulator (DEOM) and control unit (DCU) for DV-QKD reception at optical ground stations (OGS).

Let’s talk.

A CSIC spin-off built on two decades of quantum optics research.