This book constitutes revised selected papers from the 8th International Workshop on Constructive Side-Channel Analysis and Secure Design, COSADE 2017, held in Paris, France, in April 2017. The 17 papers presented in this volume were carefully reviewed and selected from numerous submissions. They were organized in topical sections named: Side-Channel Attacks and Technological Effects; Side-Channel Countermeasures; Algorithmic Aspects in Side-Channel Attacks; Side-Channel Attacks; Fault Attacks; Embedded Security; and Side-Channel Tools.