The chapters in this open access book arise out of the EU Cost Action project Cryptacus, the objective of which was to improve and adapt existent cryptanalysis methodologies and tools to the ubiquitous computing framework. The cryptanalysis implemented lies along four axes: cryptographic models, cryptanalysis of building blocks, hardware and software security engineering, and security assessment of real-world systems. The authors are top-class researchers in security and cryptography, and the contributions are of value to researchers and practitioners in these domains. This book is open access under a CC BY license.

This book constitutes the proceedings of the 2th International Workshop on Lightweight Cryptography for Security and Privacy, LightSec 2013, held in Gebze, Turkey, during May 6-7, 2013. The 10 full papers presented together with 3 invited talks were carefully reviewed and selected from 27 submissions. The papers are grouped in topical sections on efficient Implementations and designs, block cipher cryptanalysis, wireless sensor networks, and cryptographic protocols.