Optical communications in free space: the security challenge
Frédéric Grillot, professor in photonics and optical communications, May 2024.
Free-space optical communications allow large amounts of data to be transmitted, particularly in the mid-infrared wavelength range, which offers significant advantages for links subject to variable or degraded weather conditions.
Despite their many advantages, these links do not benefit from the data protection provided by the physical layer of the propagation channel. The increasing dissemination of sensitive information and the constant threat of cybercrime mean that we need to find ingenious solutions to guarantee data security.
In a recent publication in Optica, a team from Télécom Paris took up the challenge of transmission security by demonstrating a chaos-based encryption method. They demonstrated the applicability of this system over a distance of 30 metres in the far infrared.
Interviews by Isabelle Mauriac, mostly in French with English subtitles
Experiment :
free optical transmission
![[Ideas] Transmission optique en espace libre (vidéo)](https://www.telecom-paris.fr/wp-content-EvDsK19/uploads/2024/11/ideas-optique-transmission-video.jpg)
Free-space optical communications represent a promising solution for transmitting data, particularly in the mid-infrared wavelength range. By integrating photonic chaos, these transmissions are emerging as a cutting-edge technology for secure optical communications.
Frédéric Grillot, professor in photonics and optical communications, presents an experiment in free-space optical transmission at mid-infrared wavelengths.
Experiment :
chaotic encryption
![[Ideas] Cryptage chaotique des communications optiques en infrarouge (vidéo)](https://www.telecom-paris.fr/wp-content-EvDsK19/uploads/2024/11/ideas-optique-cryptage-video.jpg)
In spring 2024, a research team from the LTCI laboratory at Télécom Paris, led by Télécom Paris, took up the challenge of free-space optical transmission security by demonstrating a chaos-based encryption method, and proved the applicability of this system over a distance of 30 metres in the far infrared.
… private optical communication in free space based on chaos synchronisation in one of the atmosphere’s transparency windows. The chaotic light generated by a long-wave infrared quantum cascade laser is used to conceal the transmitted message, which is then decrypted using a double quantum cascade laser, thus guaranteeing greater confidentiality. This approach has an impact on the development of private transmissions in free space beyond conventional telecommunications networks.
Sara Zaminga, doctoral student at Télécom Paris — and Best Student Paper Award at IEEE Photonics Society Conference 2023 —, and Frédéric Grillot present this chaos-based encryption method.
![[Ideas] Communications optiques en espace libre : le défi de la sécurité (vidéo)](https://www.telecom-paris.fr/wp-content-EvDsK19/uploads/2024/05/ideas-optique-securite-video.jpg)
This configuration is ideal for applications where the protection of transmitted messages is crucial, but where high data rates are not essential, such as military applications or ground-to-satellite transmission.
Videos Michel Desnoues, Télécom Paris
