This book constitutes the refereed proceedings of the 17th International Workshop on Cryptographic Hardware and Embedded Systems, CHES 2015, held in Saint Malo, France, in September 2015. side-channel attacks on public key cryptography; side-channel analysis and fault injection attacks; higher-order side-channel attacks;

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.