A method establishes a communication between a first electronic device
associated with a first trusted authority and a second electronic device.
The method includes: making a first key available to the first device for
the communication between the first authority and the first device. A
second trusted authority, associated with the second device and distinct
and autonomous with respect to the first authority, generates a second
key in order to communicate with the second device. Furthermore, the
method includes: making the second key available to the second device;
and providing the first and second devices with a communication key, to
be used communication between the first and second devices, through at
least one of the first and second authorities.