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 [url] 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.