Behind the Scenes of iOS Security

You shouldn't include Apple in this. As of macOS Tahoe, the FileVault key you (optionally) escrow with Apple is stored in the iCloud Keychain, which is cryptographically secured by HSM-backed, rate-limited protections. You can (and should) watch ▶ this video for all the details about how iCloud is protected.

Which is a very good thing. iCloud is much more secure than most people realize because most people don’t take the 30 minutes to learn how it is architected. You can (and should) watch ▶ this video for all the details about how iCloud is protected, but especially the time-linked section. :)

This is not just encryption in transit or simplistic client-side encryption. It is end-to-end encryption, where each device's key generation is handled by your phone's Secure Enclave. This article is a decent starting point in terms of what Advanced Data Protection is: link If you want a deeper dive into the security engineering of iCloud Keychain, the second half of this Blackhat talk by Apple's head of Security Engineering & Architecture (SEAR) is really great: Synchronizing secrets: ▶ this video

There have been several comments along the lines of: "Why should I trust apple and their security, but not that of a third-party web browser?" I don't have an answer for you. But I want to recommend this talk from 7 years ago: ▶ this video That alone convinced me. Apple knows what it is doing when it comes to device security. Today, I trust them with my most sensitive data and sleep peacefully at night.

I tried 1Password but finally resolved to use iCloud keychain after watching this BlackHat 2016 video ▶ this video . I mean as far as I already trust their OS nothing can really protect me from being spied by them if they are ill intentioned, so as long as they are serious and patch their security flaw on a timely manner I can live with that. Beside it come as a free plan if you don't need more than 5GB of iCloud storage. I'd figure using an external password manager just add another third party I need to trust and the fact that 1Password offer browser app interface (on top of native) don't reassure me in any way. Of course if I'd ever need to reassess my threat model because I can't trust Apple anymore, I will quit iCloud service at the same time as their OS and go full FOSS.

They do all sorts of device key exchange, if you haven't watched the talk at Black Hat I'd highly recommend it: ▶ this video (link goes to beginning of Secure Enclave content, and later on in the talk he discusses iCloud which uses the SEP keys)

The Black Hat talk was really great: ▶ this video (link is to SEP and on-device encryption, 22:30 is iCloud stuff) > I know they said they could have accessed that San Bernardino terrorist’s iCloud backup if only they had one. Not sure if they’ve change the security architecture since then. I actually think they have, the shooting was in 2015 and iOS 10 was released in 2016 and was first to have some of the features he talks about in the video.

>So I don't really understand how this can be said to be a hardware security token. No one claimed it's a hardware security token, but the private keys are stored in iCloud Keychain, which is end-to-end encrypted. Apple cannot access your private keys even if iCloud is compromised by an external attacker or employee. If you're curious about the security engineering, you should watch the "Synchronizing secrets" part of this Black Hat talk from 2016: ▶ this video or you should read the "Synchronization security" section of the "About the security of passkeys" support doc: link

You may be interested in watching Ivan Krstić’s BlackHat talk[0], in which he details the security of the iCloud infrastructure. The use of physical one-way hash functions is involved. [0] ▶ this video

The apple security whitepaper is actually a decent place to start link There is also a blackhat talk from Ivan Krstic (one of the top security people at apple) where he goes surprisingly deep ▶ this video

Take a look at this blackhat talk from Apple's head of security Ivan Krstic, where he explains the mechanism they use to secure credentials stored in the cloud: ▶ this video

Passwords are backed up but they are end to end encrypted. Check out Cloud Key Vault, it’s a pretty cool solution for keychain (password) backups designed for adversarial clouds. Unfortunately does not apply to regular iCloud backups or most other data. But a major step forward. ▶ this video