This book constitutes the refereed proceedings of the 8th International Conference on Provable Security, ProvSec 2012, held in Chengdu, China, in September 2012. The 20 full papers and 7 short papers presented together with 2 invited talks were carefully reviewed and selected from 68 submissions. The papers are grouped in topical sections on fundamental, symmetric key encryption, authentication, signatures, protocol, public key encryption, proxy re-encryption, predicate encryption, and attribute-based cryptosystem.