Aimilia Tasidou, Pavlos S. Efraimidis, Yannis Soupionis, Lilian Mitrou, Vasilios Katos. User-centric, Privacy-Preserving Adaptation for VoIP CAPTCHA Challenges. In Nathan L. Clarke, Steven Furnell, editors, 6th International Symposium on Human Aspects of Information Security and Assurance, HAISA 2012, Crete, Greece, June 6-8, 2012. Proceedings. pages 139-149, University of Plymouth, 2012. [doi]
Abstract is missing.