This volume constitutes the papers of several workshops which were held in conjunction with the 4th International Conference on Science of Cyber Security Workshops, SciSec 2022, held in Matsue, Japan, in August 10–12, 2022. The 15 revised full papers and 3 posters were presented in this book were carefully reviewed and selected from 30 submissions.They were organized in topical sections as follows: AI Crypto and Security Workshop (AI-CryptoSec); Theory and Application of Blockchain and NFT Workshop (TA-BC-NFT); and Mathematical Science of Quantum Safety and its Application Workshop (MathSci-Qsafe).