This book constitutes the thoroughly refereed post-conference proceedings of the 13th International Conference on Information Security and Cryptology, Inscrypt 2017, held in Xi'an, China, in November 2017. The 27 revised full papers presented together with 5 keynote speeches were carefully reviewed and selected from 80 submissions. The papers are organized in the following topical sections: cryptographic protocols and algorithms; digital signatures; encryption; cryptanalysis and attack; and applications.