This book constitutes the proceedings of the Second International Conference on Codes, Cryptology and Information Security, C2SI 2017, held in Rabat, Morocco, in April 2017. The 19 regular papers presented together with 5 invited talks were carefully reviewed and selected from 72 submissions. The first aim of this conference is to pay homage to Claude Carlet for his valuable contribution in teaching and disseminating knowledge in coding theory and cryptography worldwide, especially in Africa. The second aim of the conference is to provide an international forum for researchers from academia and practitioners from industry from all over the world for discussion of all forms of cryptology, coding theory and information security.