Apple has a new support document encouraging customers to verify encrypted emails, especially security emails from Apple. The document includes Apple’s own public PGP key for those verifications. Apple noted that its current PGP key will be valid until May of 2018. PGP, or “pretty good privacy” is one of the most popular encryption schemes in general use today, through both the PGP Corporation and the open source GnuPGP. Apple posted links to both. You can subscribe to Apple’s Security-announce emails at Apple’s website.