Apple has updated its iOS Securite white paper for iOS 11 with new features that it has added to the OS since the release of iOS 11.1 and iOS 11.2. The updated document now goes into detail about Face ID, though the information here is largely similar to the one that Apple had shared previously prior to the iPhone X launch.
If you are worried about Face ID being not as secure as Touch ID or how its other aspects, the Face ID section in the document is worth a read. Other new additions to the updated document include Apple Pay Cash, Siri Suggestions, Shared Notes, TLS, CloudKit, Shared iPad, and more.
If you have never gone through this white paper before, the 77-page document highlights every key security aspect of iOS 11, including hardware level protection, file data protection, Keychain data protection, secure boot chain, and more. There is also an explanation given on how Apple Pay uses the Secure Element to safely carry out transactions while keeping your key details safe at all times.
Due to the technical nature of the document, it is not meant for everyone. However, if you are someone who values the various steps taken by Apple to keep your data safe, the white paper is worth a read. While not directly related, it is interesting to see that the iOS Security White paper from Apple does not talk about Meltdown and Spectre CPU vulnerabilities. Apple had confirmed that all its devices were affected by the two vulnerabilities, and it had released partial fixes for them with the iOS 11.2 update.