Telecommunications operators have an increasing need for security in their networks in order to face malicious intents and provide their customers with highly secure services (i.e. defense, banking, health, 4.0 industry…).
Encryption algorithm associated to more and more complex key exchange mechanisms are used to guarantee the security of transported data. However, the emergence of overpowered computers (quantum or others) could endanger the cryptographic algorithms used today. Moreover, some attack strategies consist in listening and registering the data flux today to decrypt them later. As a consequence, finding technology allowing to detect intrusions and simultaneously raising the data flux security level will be a real improvement. It has been demonstrated in the 80s that quantum physics could fulfill those requirements. For instance, Bennett and Brassard introduced in 1984 a cryptographic protocol (BB84) based on single photon polarization. Other protocols have been demonstrated using entangled photons.
With the rise of optics communications networks, it has become obvious to use those quantum encryption technology to secure data optical transmission.
Among quantum cryptography technologies, one can cite quantum key distribution (QKD) based on discrete variables (DV) and using single photons sources and detectors, and protocols such as BB84. Another way to transmit quantum keys uses continuous variables (CV) based on sending coherent states into fibers and detected by sensors close to those used in the WDM transport system.
Orange, Thales SIX GTS, Thales Alenia, KETS Quantum, Telecom Paris and a public Orange customer decide to collaborate. The goal is to deploy and study a quantum cryptography secured link between an experimental network then between 2 governmental sites.
You will participate in implementing and studying DV-QKD protocol based on integrated optics Kets Quantum technology. This will be done on dark fiber or a customer fiber of a complete line (laser, optical fiber link, photo-detectors). You will evaluate the performances in different contexts: fibers with co-propagation or dedicated fibers.
Skills (technical and scientific) and personal qualities for the job
The required skills are those corresponding to a thorough initial formation in optics/fibered photonics and quantum communication (Master 2), followed by an experimental PhD Thesis in quantum communications.
- Optically guided telecommunication systems
- CV or DV quantum cryptography
- Integrated optics and photonics
- Quantum cryptography protocols (BB84, OTP) and classical cryptography.
The applicant will have to show autonomy, analytic abilities, initiative sense and love team work: contributions to a collaborative project with frequent discussions with Orange’s expert on optical networks and cryptography (TSE).
He/She will also have to be able to communicate fluently internally and externally. In the framework of this post-doc, the applicant will have to show his/her creativity and critical thinking.

- Education
PhD thesis in experimental quantum cryptography,
Very good knowledge in signal processing and information theory
Very good knowledge of optical communications
Good knowledge of quantum cryptography protocol