This book constitutes revised selected papers from the 9th International Workshop on Constructive Side-Channel Analysis and Secure Design, COSADE 2018, held in Singapore, in April 2018.The 14 papers presented in this volume were carefully reviewed and selected from 31 submissions. They were organized in topical sections named: countermeasures against side-channel attacks; tools for side-channel analysis; fault attacks and hardware trojans; and side-channel analysis attacks.