Hi-KD : Hash-based hierarchical Key Distribution for Group Communication

Even though hierarchical group communication

is a prominent communication model for a variety of applications,

featured by hierarchical communication rules, it has

not been sufficiently investigated in the security literature.

In this paper, we introduce private hierarchical group

communication and we determine its specific confidentiality

requirements, then we propose an efficient key management

protocol satisfying those requirements. This work is

done in the frame of a national french project whose consortium

includes the international telecom company EADS,

INRIA, CNRS and ENST-Paris. The project is called Safe-

Cast and deals with group communication in PMR networks

that are used mainly by security corps (police, fire fighters,soldiers,. . . ) in areas where it is difficult to have network infrastructures, such as war battles or following a natural disaster (earthquake, tsunami, tornado, . . . ).