This book constitutes selected papers of the Second International Conference on Advanced Communication Systems and Information Security, ACOSIS 2019, held in Marrakesh, Morocco, in November 2019. The 10 full papers and 10 short papers were thoroughly reviewed and selected from 94 submissions. The papers are organized accroding to the following topical sections: wireless communications and services; vehicular communications; channel coding; construction of error correcting codes; intrusion detection techniques; wireless and mobile network security; applied cryptography.