The third International Conference on Provable Security (ProvSec 2009) was held in Guangzhou, China, November 11-13, 2009. It continued the theme of ProvableSecurity initiated by the ProvSec2007 conference in Wollongong, A- tralia. The second ProvSec conference was organized in Shanghai, China. The conference was sponsored by the Center for Advanced Computing - Cryptog- phy and Algorithms (ACAC), Macquarie University, Australia; Guangdong Key Laboratory of Information Security Technology, Sun Yat-sen University, China; andthe NationalNaturalScienceFoundationofChina (NSFC).JiwuHuangwas the...