The objective of the CalQ project is to demonstrate mid infrared atmospheric communications using a key-distribution relying on a pure deterministic process. In order to do so, the secret message will be encoded into a chaotic signal generated by a quantum cascade laser and then will be retrieved via quantum cascade detectors. Chaos is typically associated to rich and intrinsic oscillations, which can take place into a laser medium. The birth of the instabilities in a laser can lead to temporal and/or spatial chaotic dynamics, which must be distinguished from pure stochastic processes related to noise contributions. Encoded communications using diode laser chaos is a very well-known technology that has been widely used in the near infrared (telecoms) domain but that has never ever been applied to the mid infrared window. In order to make a free-space communication, the choice of the wavelength is of paramount importance that depends on the atmospheric transmission and the aerosol diffusion. Typically, wavelengths below the 8-12µm band strongly suffer from diffusion processes (clouds, fogs, etc.) while larger wavelengths get absorbed up to the microwave domain. Taking into account all these elements, it turns out that the most conducive spectral window is the 8-12 µm band. As a consequence of that, the project will perform the first ever secured transmission in this atmospheric transmission band by utilizing the chaotic dynamic outputted from a quantum cascade laser. The first observation of a chaotic dynamic in a quantum cascade laser was performed in the initial project (PhD thesis of Louise Jumpertz entirely funded by the DGA). All these elements make the CaLQ project strongly innovating. In addition to the proof of concept itself, the project will investigate/study the global problematic of the chaotic communications in the mid infrared window as well as identifying the key mechanisms and parameters. The project relies on a solid consortium with well-known experts in the different fields and having an excellent complementarity. TPT is in charge of the management of the project as well as the realization of the free-space communication system based on the chaotic regime from the quantum cascade laser. In order to do so, the two required building blocks will be developed by MIRS for the laser part and by the III-V Lab for the detection one. TAS will bring his strong expertise in the design of the chaotic communication system and in the final validation. The technology developed in the CaLQ project is of first importance for various applications both at the civil and defense levels. The results will feed the development of secured and furtive communications on landscapes without any infrastructures. If the system is enough compact and energy efficient, its deployment between airborne or space objects and the ground or terrestrial communication between two ground stations is envisioned with the view to create a secured communication network. High-speed communications are of paramount importance especially for applications requiring a fast transmission speed like between a drone and its base station.