This book constitutes the thoroughly refereed post-conference proceedings of the 12th International Conference on Information Security and Cryptology, Inscrypt 2016, held in Beijing, China, in November 2016. The 32 revised full papers presented were carefully reviewed and selected from 93 submissions. The papers are organized in topical sections on symmetric ciphers; public-key cryptosystems; signature and authentication; homomorphic encryption; leakage-resilient; post-quantum cryptography;  commitment and protocol; elliptic curves; security and implementation.