Thanks for this reply.
I think that it is possible to make it without changing the barells.
I don't know the proper english words for that, but in a key, we have a physical part (for the barrels) and an electronic part (the remote, of course, but also the chip that communicates with the ECU).
I have already ordered a new key, so I can open my doors and set up an anti-theft system on the wheel (because the burglars have my keys and might be looking for my car).
My question is as follows : If I buy a used ECU + his master key on ebay, is that possible to make a new master key from that one to another one that has the same physical part as my current one? This would allow me to stick with my current barrels.
Another question :
I am not sure, but I thought that there were 3 keys when I bought the car : Two with the built-in remote, and a last one without remote. Can anyone confirm?