This book constitutes the refereed proceedings of the 6th International Conference on Provable Security, ProvSec 2012, held in Chengdu, China, in September 2012. The 16 full papers and 4 short papers presented were carefully reviewed and selected from 66 submissions. The papers are grouped in topical sections on signature schemes, foundations, leakage resilence and key escrow, encryption schemes, and information theoretical security.