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.

Popular Stories

iphone air thickness

Apple Said to Cut iPhone Air Production Amid Underwhelming Sales

Friday October 17, 2025 8:29 am PDT by
Apple plans to cut production of the iPhone Air amid underwhelming sales performance, Japan's Mizuho Securities believes (via The Elec). The Japanese investment banking and securities firm claims that the iPhone 17 Pro and iPhone 17 Pro Max are seeing higher sales than their predecessors during the same period last year, while the standard iPhone 17 is a major success, performing...
HomePod mini and Apple TV

Apple's Next Rumored Products: New HomePod Mini, Apple TV, and More

Thursday October 16, 2025 9:13 am PDT by
Apple on Wednesday updated the 14-inch MacBook Pro, iPad Pro, and Vision Pro with its next-generation M5 chip, but previous rumors have indicated that the company still plans to announce at least a few additional products before the end of the year. The following Apple products have at one point been rumored to be updated in 2025, although it is unclear if the timeframe for any of them has...
maxresdefault

Here's Everything Apple Announced Today

Wednesday October 15, 2025 3:54 pm PDT by
We didn't get a second fall event this year, but Apple did unveil updated products with a series of press releases that went out today. The M5 chip made an appearance in new MacBook Pro, Vision Pro, and iPad Pro models. Subscribe to the MacRumors YouTube channel for more videos. We've rounded up our coverage and highlighted the main feature changes for each device below. MacBook Pro M5...
14 inch MacBook Pro Keyboard

New 14-Inch MacBook Pro Has Two Key Upgrades Beyond the M5 Chip

Thursday October 16, 2025 8:31 am PDT by
Apple on Wednesday updated the 14-inch MacBook Pro base model with an M5 chip, and there are two key storage-related upgrades beyond that chip bump. First, Apple says the new 14-inch MacBook Pro offers up to 2× faster SSD performance than the equivalent previous-generation model, so read and write speeds should get a significant boost. Apple says it is using "the latest storage technology," ...
iOS 26 Feature

iOS 26.1 to iOS 26.4 Will Add These New Features to Your iPhone

Saturday October 18, 2025 11:00 am PDT by
iOS 26 was released last month, but the software train never stops, and iOS 26.1 beta testing is already underway. So far, iOS 26.1 makes both Apple Intelligence and Live Translation on compatible AirPods available in additional languages, and it includes some other minor changes across the Apple Music, Calendar, Photos, Clock, and Safari apps. More features and changes will follow in future ...
iOS 26

iOS 26.0.2 Update for iPhones Coming Soon

Friday October 17, 2025 7:35 am PDT by
Apple's software engineers continue to internally test iOS 26.0.2, according to MacRumors logs, which have been a reliable indicator of upcoming iOS versions. iOS 26.0.2 will be a minor update that addresses bugs and/or security vulnerabilities, but we do not know any specific details yet. The update will likely be released by the end of next week. Last month, Apple released iOS 26.0.1,...
Apple iPad Pro hero M5

Apple Debuts New iPad Pro With M5 Chip, Faster Charging, and More

Wednesday October 15, 2025 6:16 am PDT by
Apple today announced the next-generation iPad Pro, featuring the custom-designed M5, C1X, and N1 chips. The M5 chip has up to a 10-core CPU, with four performance cores and six efficiency cores. It features a next-generation GPU with Neural Accelerator in each core, allowing the new iPad Pro to deliver up to 3.5x the AI performance than the previous model, and a third-generation ray-tracing ...
M5 MacBook Pro

Apple Announces New 14-Inch MacBook Pro With M5 Chip

Wednesday October 15, 2025 6:07 am PDT by
Apple today updated the 14-inch MacBook Pro base model with its new M5 chip, which is also available in updated iPad Pro and Vision Pro models. In addition, the base 14-inch MacBook Pro can now be configured with up to 4TB of storage on Apple's online store, whereas the previous model maxed out at 2TB. However, the maximum amount of unified RAM available for this model remains 32GB. Like...
m4 macbook air blue

M5 MacBook Air Coming Spring 2026 With M5 Mac Studio and Mac Mini in Development

Thursday October 16, 2025 3:57 pm PDT by
Apple plans to launch MacBook Air models equipped with the new M5 chip in spring 2026, according to Bloomberg's Mark Gurman. Apple is also working on M5 Pro and M5 Max MacBook Pro models that will come early in the year. Neither the MacBook Pro models nor the MacBook Air models are expected to get design changes, with Apple focusing on simple chip upgrades. In the case of the MacBook Pro, a m...

Top Rated Comments

mtneer Avatar
59 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
59 months ago
Thank you Apple
Score: 14 Votes (Like | Disagree)
mtneer Avatar
59 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
59 months ago
I’m glad Apple is very proactive with hardware based security improvements.
Score: 6 Votes (Like | Disagree)
0924487 Avatar
59 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
59 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)