Antonio Lioy Marius Marian Natalia Moltchanova Massimiliano Pala PKI past, present and future. 18-29 2006 5 Int. J. Inf. Sec. 1 http://dx.doi.org/10.1007/s10207-005-0077-9 db/journals/ijisec/ijisec5.html#LioyMMP06