Book excerpt: This book constitutes the refereed proceedings of the 9th International Conference on Security, Privacy, and Applied Cryptography Engineering, SPACE 2019, held in Gandhinagar, India, in December 2019. The 12 full papers presented were carefully reviewed and selected from 24 submissions. This annual event is devoted to various aspects of security, privacy, applied cryptography, and cryptographic engineering. This is a very challenging field, requiring the expertise from diverse domains, ranging from mathematics to solid-state circuit design.