Apple is infamous for guarding its secrets tightly, so it came as a big surprise that the preview version of iOS 10 it released at WWDC has an unencrypted kernel. According to a spokesperson, though, Cupertino did it on purpose, because by leaving it unencrypted, the company was "able to optimize the operating system's performance without compromising security." The kernel is the heart of an operating system, and on iOS, it's in charge of security and managing what parts of an iPhone or an iPad apps can access. Apple used to keep it under several layers of protection -- now that security researchers can examine it more closely, bugs could come to light more quickly than before.