This book constitutes the refereed proceedings of the 9th International Conference on the Theory and Application of Cryptographic Techniques in Africa, AFRICACRYPT 2017, held in Dakar, Senegal, in May 2017. The 13 papers presented in this book were carefully reviewed and selected from 40 submissions. The papers are organized in topical sections on cryptographic schemes, side-channel analysis, differential cryptanalysis, applications, and number theory.