Apple Made Sudden Security Changes to its Chips in Fall 2020

Apple made unusual mid-production hardware changes to the A12, A13, and S5 processors in its devices in the fall of 2020 to update the Secure Storage Component, according to Apple Support documents.

a13 bionic mockup
According to an Apple Support page, spotted by Twitter user Andrew Pantyukhin, Apple changed the Secure Enclave in a number of products in the fall of 2020:

Note: A12, A13, S4, and S5 products first released in Fall 2020 have a 2nd-generation Secure Storage Component; while earlier products based on these SoCs have 1st-generation Secure Storage Component.

The Secure Enclave is a coprocessor that is used for data protection and authentication with Touch ID and Face ID. The purpose of the Secure Enclave is to handle keys and other information, such as biometrics, that are sensitive enough to not be handled by the Application Processor. This data is stored in a Secure Storage Component inside the Secure Enclave, which is the specific part that Apple changed last year.

The explanation in Apple's support document suggests, at minimum, that the eighth-generation entry-level iPad, Apple Watch SE, and HomePod mini have different Secure Enclaves compared to older devices with the same chip.

However, there are a number of discrepancies in Apple's support document. Despite Apple explaining that A13 products "first released in Fall 2020 have a 2nd-generation Secure Storage Component," there was no device with an A13 chip "first released in Fall 2020." The last device to be released with an A13 chip was the iPhone SE in February 2020.

If the change was, in fact, made to all newly-manufactured devices with these chips, the affected devices would include the iPhone XR, ‌iPhone‌ 11, ‌iPhone SE‌, and fifth-generation iPad mini, as well as the newly-released eighth-generation ‌iPad‌, ‌Apple Watch SE‌, and ‌HomePod mini‌.

a12 a13 s5 secure enclave change
To make matters more confusing, the table listing the multiple versions of the Secure Enclave's storage component in the feature summary omits the S4 chip with a second-generation Secure Storage Component, despite the rubric claiming that such a chip exists. The Apple Watch Series 4 was the only device to contain an S4 chip, and this device was discontinued in September 2019, long before the second-generation Secure Storage Component was implemented in the fall of 2020. It is possible that part of this lack of clarity relates to the fact that the A12 and S4 chips introduced the first-generation Secure Storage Component.

New devices containing the A14 or S6 chip, such as the iPhone 12, ‌iPhone 12‌ Pro, fourth-generation iPad Air, and Apple Watch Series 6, also have the updated Secure Enclave.

Although the change took place in the fall of 2020, the support document detailing the alteration was published in February 2021. The full PDF version of Apple's Platform Security Guide reveals the difference between the first and second-generation Secure Storage Component:

The 2nd-generation Secure Storage Component adds counter lockboxes. Each counter lockbox stores a 128-bit salt, a 128-bit passcode verifier, an 8-bit counter, and an 8-bit maximum attempt value. Access to the counter lockboxes is through an encrypted and authenticated protocol.

Counter lockboxes hold the entropy needed to unlock passcode-protected user data. To access the user data, the paired Secure Enclave must derive the correct passcode entropy value from the user's passcode and the Secure Enclave's UID. The user's passcode can't be learned using unlock attempts sent from a source other than the paired Secure Enclave. If the passcode attempt limit is exceeded (for example, 10 attempts on iPhone), the passcode-protected data is erased completely by the Secure Storage Component.

This appears to be a countermeasure against password-cracking devices, such as GrayKey, which attempt to break into iPhones by guessing the passcode an infinite number of times, using exploits that allow for infinite incorrect password attempts.

The change appears to have been significant enough for Apple to justify an entire "second-generation" version of the Secure Enclave's storage. It is certainly unusual for Apple to change a component in its chips mid-way through production, but Apple likely deemed the security upgrade important enough to roll it out to all relevant new devices from the fall onwards, rather than just devices with the latest A14 and S6 chips.

Top Rated Comments

mtneer Avatar
26 months ago
I wonder if this was in response to a major hardware security breach? Does that mean that devices released before the patch are now vulnerable?
Score: 18 Votes (Like | Disagree)
Serban55 Avatar
26 months ago
Thank you Apple
Score: 14 Votes (Like | Disagree)
mtneer Avatar
26 months ago

everything old become vulnerable.
The article says that the cutoff is "Fall 2020".. that's 6 months ago. We aren't talking about age-old vintage devices here..
Score: 8 Votes (Like | Disagree)
Realityck Avatar
26 months ago
I’m glad Apple is very proactive with hardware based security improvements.
Score: 6 Votes (Like | Disagree)
h3ysw5nkan Avatar
26 months ago

He’s too busy saving $0.05 per iPhone by not including the charger until the guise of “saving the planet!”.
It’s more like $5 per charger, which isn’t insignificant.
Score: 6 Votes (Like | Disagree)
Serban55 Avatar
26 months ago

I wonder if this was in response to a major hardware security breach? Does that mean that devices released before the patch are now vulnerable?
everything old become vulnerable.
Score: 3 Votes (Like | Disagree)

Popular Stories

maxresdefault

Apple Announces WWDC 2023 Event Taking Place June 5 to 9

Wednesday March 29, 2023 9:58 am PDT by
Apple today announced that its 34th annual Worldwide Developers Conference will take place from Monday, June 5 to Friday, June 9. Like WWDC 2020, 2021, and 2022, WWDC 2023 will be an online event for the most part, and it will be open to all developers at no cost. Subscribe to the MacRumors YouTube channel for more videos. Apple will provide online sessions and labs, which will allow...
iPhone 15 Pro Buttons CAD Leak

iPhone 15 Pro Low-Energy Chip to Allow Solid-State Buttons to Work When Device is Off or Out of Battery

Wednesday March 29, 2023 1:54 am PDT by
The iPhone 15 Pro and Pro Max will use a new ultra-low energy microprocessor allowing certain features like the new capacitive solid-state buttons to remain functional even when the handset is powered off or the battery has run out, according to a source that shared details on the MacRumors forums. CAD-based render of new solid-state buttons on iPhone 15 Pro models The source of this rumor is ...
CarPlay Phone Call

General Motors to Phase Out Apple CarPlay Starting This Year in EV Transition

Friday March 31, 2023 8:43 am PDT by
General Motors (GM) will phase out Apple CarPlay and Android Auto in its vehicles starting this year, shifting to a built-in infotainment system co-developed with Google (via Reuters). GM owns Buick, Cadillac, Chevrolet, and GMC in the United States. It will stop offering Apple CarPlay and Android Auto starting with the 2024 Chevrolet Blazer, which goes on sale this summer. The company plans ...
iPhone 15 Pro Multi Purpose button Mute Switch Feature Green 2

iPhone 15 Pro Rumored to Feature Multi-Use Action Button Instead of Mute Switch

Wednesday March 29, 2023 7:28 am PDT by
iPhone 15 Pro and iPhone 15 Pro Max models are rumored to feature a customizable Action button like the Apple Watch Ultra, according to a MacRumors forum member who leaked accurate details about the Dynamic Island on iPhone 14 Pro models last year. The source claimed the Action button will replace the Ring/Silent switch that has been included on every iPhone model since 2007. They did not...
iOS 16

iOS 16.4 Now Available for Your iPhone With These 8 New Features

Friday March 31, 2023 8:55 am PDT by
Following six weeks of beta testing, iOS 16.4 was released to the public this week. The software update includes a handful of new features and changes for the iPhone 8 and newer. To install an iOS update, open the Settings app on the iPhone, tap General → Software Update, and follow the on-screen instructions. Below, we have recapped eight new features and changes added with iOS 16.4,...
iOS 17 on Phone Feature

Three New iOS Features Coming to Your iPhone Following Apple Music Classical

Thursday March 30, 2023 7:13 am PDT by
With the Apple Music Classical app and an Apple Pay Later early access program now available, the list of previously-announced iOS features that have yet to launch is beginning to shrink. However, there are still a few features we are waiting for. Below, we have recapped three more iOS features that are expected to launch in 2023, including an Apple Card savings account for Daily Cash,...
apple mixed reality headset concept by david lewis and marcus kane

Kuo: Apple Mixed-Reality Headset May Not Appear at WWDC as Mass Production Pushed Back Yet Again

Thursday March 30, 2023 4:50 am PDT by
Apple has again pushed back mass production of its mixed-reality headset and the device may not appear at this year's Worldwide Developers Conference (WWDC), Apple analyst Ming-Chi Kuo today said. Apple headset concept by David Lewis and Marcus Kane In a tweet, Kuo explained that Apple "isn't very optimistic" about whether the headset will be able to create an "iPhone moment." As a result,...