Åsa Hagström Sushil Jajodia Francesco Parisi-Presicce Duminda Wijesekera 44-58 2001 conf/csfw/2001 CSFW http://csdl.computer.org/comp/proceedings/csfw/2001/1146/00/11460044abs.htm db/conf/csfw/csfw2001.html#HagstromJPW01