This book constitutes the refereed proceedings of the 13th International Workshop on Security
IWSEC 2018 held in Sendai Japan in September 2018. The 18 regular papers and 2 short papers
presented in this volume were carefully reviewed and selected from 64 submissions. They were
organized in topical sections named: Cryptanalysis Implementation Security Public-Key
Primitives Security in Practice Secret Sharing Symmetric-Key Primitives and Provable
Security.