This book constitutes the refereed proceedings of the 12th International Joint Conference on E-Business and Telecommunications, ICETE 2015, held in Colmar, France, in July 2015. ICETE is a joint international conference integrating four major areas of knowledge that are divided into six corresponding conferences: International Conference on Data Communication Networking, DCNET; International Conference on E-Business, ICE-B; International Conference on Optical Communication Systems, OPTICS; International Conference on Security and Cryptography, SECRYPT; International Conference on Wireless Information Systems, WINSYS; and International Conference on Signal Processing and Multimedia, SIGMAP. The 23 full papers presented together with an invited paper in this volume were carefully reviewed and selected from 218 submissions. The papers cover the following key areas of e-business and telecommunications: data communication networking; e-business; optical communication systems; security and cryptography; signal processing and multimedia applications; wireless information networks and systems.