This book constitutes the thoroughly refereed post-conference proceedings of the 18th International Conference on Smart Card Research and Advanced Applications, CARDIS 2019, held in Prague, Czech Republic, in November 2019. The 15 revised full papers presented in this book were carefully reviewed and selected from 31 submissions. The papers are organized in the following topical sections: system-on-a-chip security; post-quantum cryptography; side-channel analysis; microarchitectural attacks; cryptographic primitives; advances in side-channel analysis. CARDIS has provided a space for security experts from industry and academia to exchange on security of smart cards and related applications.