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
38 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
38 months ago
Thank you Apple
Score: 14 Votes (Like | Disagree)
mtneer Avatar
38 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
38 months ago
I’m glad Apple is very proactive with hardware based security improvements.
Score: 6 Votes (Like | Disagree)
0924487 Avatar
38 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
38 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

Apple Logo Spotlight

Source: Apple to Announce New Products This Week

Sunday March 3, 2024 11:38 am PST by
Apple plans to announce new products with press releases on its website this week, a proven source familiar with the matter told MacRumors. While the products that Apple plans to announce have not been disclosed, there are rumors about new iPads, Macs, and accessories. It is unclear exactly what will be announced this week. Bloomberg's Mark Gurman today reiterated that Apple is planning new...
Apple Maps vs Google Maps Feature

Apple Maps vs. Google Maps: Which Is Better?

Friday March 1, 2024 7:10 am PST by
Apple Maps has been providing navigational guidance to Apple users for almost 13 and a half years now, and much has changed about the app in that time. However, according to data from Canalys, the overwhelming majority of iPhones in the U.S. still have Google Maps downloaded as an alternative to Apple Maps, which comes preinstalled on all iPhones. We want to hear from MacRumors readers. Which do...
apple tv plus banner

Apple TV+ Gains Over 50 Movies for a Limited Time

Friday March 1, 2024 6:29 am PST by
Apple TV+ today gained over 50 movies, adding to its back catalog of content for a limited time. The collection includes a large number of popular and classic titles. Subscribers can access the movies in a "Great Movies on Apple TV+" section in the Apple TV app. Some titles are also available in 3D. Movies in the collection include: 21 Jump Street 300 American Sniper Argo ...
iPad Air 12

Gurman: No Apple Event Planned for Upcoming iPads and Macs

Sunday March 3, 2024 5:09 am PST by
Apple does not plan to hold a traditional event to unveil new iPads and Macs, according to Bloomberg's Mark Gurman. Instead, he said Apple plans to announce the products on its website with a "series of online videos and marketing campaigns." If this plan is accurate, we can expect the new products to be announced with press releases on the Apple Newsroom website. Gurman expects Apple to...
airpods pro 2 pink

Apple Releases New Beta Firmware for AirPods Pro 2

Thursday February 29, 2024 11:41 am PST by
Apple today introduced a new beta firmware update for the AirPods Pro 2, both the USB-C and Lightning versions. The new firmware is version 6E188, up from the prior 6B34 firmware released in December. Apple does not often provide details or notes on what features might be included in the refreshed firmware, so it is unclear what's new. Note that this software is limited to developers at the...