agram of an exemplary computer system operative to perform the functions of the respective nodes and the ephemerizer depicted in FIG. 2; [0028]FIGS. 4a, 4 b and 4 c are a flow diagram that depict an exemplary method of operation of the system depicted in FIG. 2; and [0029]FIGS. 5a and 5 b are a flow diagram that depict another exemplary method of operation of the system depicted in FIG. 2.