Yes from 1986 to 1996-99. It is legal since then.

Source: https://fr.wikipedia.org/wiki/Chiffrement#En_France (in french)

Slightly of topic, but they also make DNA tests to determine paternity illegal without the consent of the mother! I recommend all new fathers to do it quietly (without ruffling any feathers), costs basically nothing (< $200) as compared to the pain/devastation finding out 10-20-30 years later that the children you raised were not yours. Doesn't happen a lot, but can happen to anyone. In France you'll go to jail for doing this, or at least have to create a scene with your partner.

Australia's been pursuing it since 2018:

https://youtube.com/watch?v=i326eNOa6Us&feature=share7

Personally, I have nothing to hide. But I enjoy hiding as much as I can for the enjoyment of the technological challenge and also the absolute "Fuck You, Forever" to those sociopaths that want to control that which they have no natural right to control.

No ?