This book constitutes the refereed proceedings of the 12th International Workshop on Security
IWSEC 2017 held in Hiroshima Japan in August September 2017. The 11 regular papers and 3
short papers presented in this volume were carefully reviewed and selected from 37 submissions.
They were organized in topical sections named: post-quantum cryptography system security
public key cryptosystems cryptanalysis and cryptographic protocols.
