This book constitutes the proceedings of the First International Conference on Frontiers in Cyber Security, held in Chengdu, China, in November 2018. The 18 full papers along with the3 short papers presented were carefully reviewed and selected from 62 submissions. The papers are organized in topical sections, namely: symmetric key cryptography, public key cryptography, post-quantum cryptography, cloud security and data deduplication, access control, attack and behavior detection, system and network security, security design.

This book constitutes the refereed proceedings of the 5th International Conference on Frontiers in Cyber Security, FCS 2022, held in Kumasi, Ghana, during December 13-15, 2022. The 26 full papers were included in this book were carefully reviewed and selected from 65 submissions. They were organized in topical sections as follows: ioT Security; artificial intelligence and cyber security; blockchain technology and application; cryptography; database security; quantum cryptography; and network security.