Whitfield Diffie, winner of the Turing Award, world-renowned Cryptologist and Security Technologist and chief scientist at Cryptic Labs, delivers a keynote speech during the opening ceremony of China International Big Data Industry Expo 2019 in Guiyang, southwest China's Guizhou Province, May 26, 2019. An international expo on big data opened Sunday in southwest China's Guizhou Province, focusing on the latest innovation of the technology and its applications. The four-day China International Big Data Industry Expo 2019 in the provincial capital of Guiyang will be attended by 448 enterprises from 59 countries and regions, according to the organizing committee. (Xinhua/Ou Dongqu)