The recent ACM Cloud Computing Security Workshop in Chicago was devoted specifically to cloud security. Speakers included Whitfield Diffie, a cryptographer and security researcher who, in 1976, helped solve a fundamental problem of cryptography: how to securely pass along the "keys" that unlock encrypted material for intended recipients. Diffie, now a visiting professor at Royal Holloway, University of London, was until recently a chief security officer at Sun Microsystems. He sat down with Technology Review's chief correspondent. Read the full article. [Technology Review]