This book constitutes revised selected papers of the First International Conference on Computing Science, Communication and Security, COMS2 2020, held in March 2020. Due to the COVID-19 pandemic the conference was held virtually. The 26 full papers and 1 short paper were thoroughly reveiwed and selected from 79 submissions. Papers are organised according to the topical sections on artificial intelligence and machine learning; network, communication and security; computing science.