One of Apple's quietest announcements at WWDC might also be its most important. The company has introduced a brand new file system, simply called Apple File System (APFS) that makes security its centerpiece. It offers a unified encryption method for virtually every device Apple makes, ranging from the Apple Watch to the Mac. That includes multikey encryption, which makes it tough to crack even if you have physical access to the storage. In short, the FBI won't be happy: Encryption is now a core part of the operating system, not just something bolted on after the fact.