This book constitutes the thoroughly refereed post-proceedings of the Third International Conference on Security in Communication Networks, SCN 2002, held in Amalfi, Italy in September 2002. The 24 revised full papers presented together with two invited papers were carefully selected from 90 submissions during two rounds of reviewing and revision. The papers are organized in topical sections on forward security, foundations of cryptography, key management, cryptanalysis, systems security, digital signature schemes, zero knowledge, and information theory and secret sharing.