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#ios#secureenclave#icloudkeychain

Behind the Scenes of iOS Security

Black Hat

281K subscribers • 47 videos on Hallway • Conference channel

YouTube
  • Recommended by 9 people: 9 on Hacker News.
  • A classic. People kept recommending it from 2016 to 2026.
  • Presented by Ivan Krstic, Apple's head of Security Engineering
  • May be out of date. Uploaded 10 years ago, in an area where tools change fast.

Advanced. Deep dive for people who know the field.

126K views10 years ago9 recommendations

SecurityMobile developmentiOS and SwiftUICryptographyWeb and application security

Ivan Krstic explains the cryptographic design and implementation of iOS security mechanisms including HomeKit, Auto Unlock, and iCloud Keychain.

by Ivan Krstic With over a billion active devices and in-depth security protections spanning every layer from silicon to software, Apple works to advance the state of the art in mobile security with every release of iOS. We will discuss three iOS security mechanisms in unprecedented technical detail, offering the first public discussion of one of them new to iOS 10. HomeKit, Auto Unlock and iCloud Keychain are three Apple technologies that handle exceptionally sensitive user data – controlling devices (including locks) in the user's home, the ability to unlock a user's Mac from an Apple Watch, and the user's passwords and credit card information, respectively. We will discuss the cryptographic design and implementation of our novel secure synchronization fabric which moves confidential data between devices without exposing it to Apple, while affording the user the ability to recover data in case of device loss. Data Protection is the cryptographic system protecting user data on all iOS devices. We will discuss the Secure Enclave Processor present in iPhone 5S and later devices and explain how it enabled a new approach to Data Protection key derivation and brute force rate limiting within a small TCB, making no intermediate or derived keys available to the normal Application Processor. Traditional browser-based vulnerabilities are becoming harder to exploit due to increasingly sophisticated mitigation techniques. We will discuss a unique JIT hardening mechanism in iOS 10 that makes the iOS Safari JIT a more difficult target.

Why it's here

9 people recommend this

What people say. Recommended as an exceptionally detailed look at iOS security, the Secure Enclave, and iCloud Keychain encryption.

karlsheaon Hacker News • Recommends

On “Apple, in Sign of Health Ambitions, Adds Medical Records Feature for iPhone”

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

karlsheaon Hacker News • Recommends

On “Apple, in Sign of Health Ambitions, Adds Medical Records Feature for iPhone”

The Black Hat talk was really great: link to 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.

Twisellon Hacker News • Recommends

On “Ask HN: How comfortable do you feel using cloud-based password managers?”

I tried 1Password but finally resolved to use iCloud keychain after watching this BlackHat 2016 video link to 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…

dilippkumaron Hacker News • Recommends

On “Apple confirms it's breaking iPhone web apps in the EU on purpose”

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: link to 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.

jesseendahlon Hacker News • Recommends

On “UK backing down on Apple encryption backdoor after pressure from US”

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: link to this video

eddygon Hacker News • Recommends

On “Microsoft gave FBI set of BitLocker encryption keys to unlock suspects' laptops”

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 link to this video for all the details about how iCloud is protected.

eddygon Hacker News • Recommends

On “MS confirms it will give the FBI your Windows PC data encryption key if asked”

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 link to this video for all the details about how iCloud is protected, but especially the time-linked section. :)

arkadiyton Hacker News • Recommends

On “The limitations of Android N Encryption”

For a really in-depth dive about the iOS class keys system he mentions I recommend this 2016 blackhat talk by Ivan Krstic (head of security at Apple): link to this video (relevant portion starts at 6:56)

abaloneon Hacker News • Recommends

On “Apple moves to store iCloud keys in China, raising human rights fears”

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. link to this video

xmodemon Hacker News • Recommends

On “Apple iMac Pro and Secure Storage”

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: link to this video

ghostpepperon Hacker News • Recommends

On “FBI tells lawmakers it can't access Dayton gunman's phone”

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 link to this video

eddygon Hacker News • Recommends

On “Luxury Surveillance”

You may be interested in watching Ivan Krstić’s BlackHat talk0, in which he details the security of the iCloud infrastructure. The use of physical one-way hash functions is involved. 0 link to this video

jesseendahlon Hacker News • Recommends

On “Tailscale doesn't want your password”

>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: link to this video or you should read the "Synchronization security" section of the "About the security of passkeys" support doc: link

tedmistonon Hacker News • Mentions

On “iPhone 7”

I found the talk (though I don't pretend to understand it all), video & slides are online if others are interested. Behind the Scenes with iOS Security Abstract - link Slides - link Video - link to this video

IBMon Hacker News • Mentions

On “Chinese authorities detain Apple employees suspected of selling customer data”

Given the way iCloud security works I'm not sure iCloud was breached at all 1. Other reports seem to indicate that it was employees at Apple stores and third party resellers who had access to names, phone numbers and Apple IDs 2. Presumably they would try to phish them later on. 1 link to this video 2 link

Shankon Hacker News • Mentions

On “Our Approach to Privacy”

…e been different. The FBI would have already had a backdoor or been able to trivially break the device, or they would have complied and created an iOS variant to break in. All we know is what they stood their ground on, and the effort that was required for the FBI to get in. iOS 10 security white paper: link Talk about iOS security at Black Hat: link to this video…