This volume constitutes the refereed proceedings of the Second IFIP WG 11.2 International Workshop on Information Security Theory and Practices: Smart Devices, Convergence and Next Generation Networks, WISTP 2008, held in Seville, Spain, in May 2008. The 10 revised full papers presented were carefully reviewed and selected from numerous submissions for inclusion in the book; they examine the rapid development of information technologies and the transition to next generation networks. The papers focus on the security of these complex and resource-constrained systems and are organized in topical sections on smart devices, network security, convergence, and cryptography