One of the cryptography world's biggest names has returned to Apple. According to a Reuters report, former Silent Circle CTO Jon Callas is employed by Apple as of this month, working in an undisclosed capacity. (Reached by The Verge, Apple confirmed the news.) Callas is best known for his work on the pioneering PGP encryption system, including authoring the openPGP standard for IETF and developing PGP's universal server software. He co-founded the secure-messaging system Silent Circle in 2012.
Callas has worked for Apple twice before, first from 1995 to 1997 and again from 2009 to 2011. During the second period, he oversaw the upgrades to FileVault in OS X Lion, the first full-disk encryption system to cover the computer's entire home directory. It's unclear what Callas will be working on at Apple, but the move underscores Apple's commitment to disk encryption on its devices, a feature that was at the center of the San Bernardino case earlier this year.