This book constitutes the refereed post-conference proceedings of the 4th International Workshop on Lightweight Cryptography for Security and Privacy, LightSec 2015, held in Bochum, Germany, in September 2015. The 9 full papers presented were carefully reviewed and selected from 17 submissions. The papers are organized in the following topical sections: cryptanalysis, lightweight constructions, implementation challenges.

This book constitutes the thoroughly refereed post-conference proceedings of the 13th International Conference on Smart Card Research and Advanced Applications, CARDIS 2014, held in Paris, France, in November 2014. The 15 revised full papers presented in this book were carefully reviewed and selected from 56 submissions. The papers are organized in topical sections on Java cards; software countermeasures; side-channel analysis; embedded implementations; public-key cryptography and leakage and fault attacks.