1. Cyber Security Engineering Area, Graduate School of Engineering, Osaka University, Japan. E-mail: sunshine.tian86@gmail.com
2. Computer and Information Science, University of Oregon, USA. E-mail: yingjiul@uoregon.edu
3. School of Information Systems, Singapore Management University, Singapore. E-mails: robertdeng@smu.edu.sg, binujucse3@gmail.com
4. School of Computing and Information Technology, University of Wollongong, NSW, Australia. E-mail: gyang@uow.edu.au