This bookconstitutes the refereed proceedings of the 12th International Joint Conferenceon E-Business and Telecommunications, ICETE 2015, held in Colmar, France, inJuly 2015. ICETE is a joint international conference integrating four majorareas of knowledge that are divided into six corresponding conferences:International Conference on Data Communication Networking, DCNET; InternationalConference on E-Business, ICE-B; International Conference on OpticalCommunication Systems, OPTICS; International Conference on Security andCryptography, SECRYPT; International Conference on Wireless InformationSystems, WINSYS; and International Conference on Signal Processing andMultimedia, SIGMAP.The 23 fullpapers presented together with an invited paper in this volume were carefully reviewed and selected from 218 submissions. Thepapers cover the following key areas of e-business and telecommunications: datacommunication networking; e-business; optical communication systems; securityand cryptography; signal processing and multimedia applications; wirelessinformation networks and systems.