This book constitutes the refereed proceedings of two workshops held at the 13th International Conference on Security and Privacy in Communications Networks, SecureComm 2017, held in Niagara Falls, ON, Canada, in October 2017: the 5th International Workshop on Applications and Techniques in Cyber Security, ATCS 2017, and the First Workshop on Security and Privacy in the Internet Of Things, SePrIoT 2017.The 22 revised regular papers  were carefully reviewed and selected from 105 submissions. The topics range from access control; language-based security; malicious software; network security; cloud security; software security; operating system security; privacy protection, database security, security models; and many more.The SePrIoT workshop targets to address novel approaches in security and privacy. The papers focuse, amongst others, on novel models, techniques, protocols, algorithms, or architectures.