This book constitutes the proceedings of the 15th IMA International Conference on Cryptography and Coding, IMACC 2015, held at Oxford, UK, in December 2015. The 18 papers presented together with 1 invited talk were carefully reviewed and selected from 36 submissions. The scope of the conference was on following topics: authentication, symmetric cryptography, 2-party computation, codes, Boolean functions, information theory, and leakage resilience.