What is Blockchain | Shai Rubin September 13, 2017 Blockchain explained. Shai Rubin, CTO of Citi Innovation Lab, explains in an easy and simple way the basics of blockchain. Share this: Click to share on X (Opens in new window) X Click to share on Facebook (Opens in new window) Facebook Related Posted in Grow, Imagine and tagged anna, blockchain, blockchain-concept, blockchain-explainer, fred