This volume constitutes the refereed proceedings of the 9th IFIP WG 11.2 International Conference(formerly Workshop) on Information Security Theory and Practices, WISTP 2015, held in Heraklion, Crete, Greece, in August 2015. The 14 revised full papers and 4 short papers presented together were carefully reviewed and selected from 52 submissions. WISTP 2015 sought original submissions from acade…