Mithun Acharya Joao Girão Dirk Westhoff Secure Comparison of Encrypted Data in Wireless Sensor Networks. 47-53 2005 conf/wiopt/2005 WiOpt http://csdl.computer.org/comp/proceedings/wiopt/2005/2267/00/22670047abs.htm db/conf/wiopt/wiopt2005.html#AcharyaGW05