Touch ID and A7 Secure Enclave Detailed in Updated Apple Security Document

Apple today posted an updated security document [PDF] on its iPhone in Business site, offering details on the inner workings of both Touch ID and the "Secure Enclave" built into Apple's A7 processor (via TechCrunch).

Since its 2013 release, Touch ID has faced scrutiny over privacy concerns from both users and government officials, and while Apple has previously offered few details on how Secure Enclave works, it has assured users that the system stores only fingerprint data rather than images.

touchid
According to the updated security document, Secure Enclave is a coprocessor within the A7 chip that uses a secure boot process to ensure that its separate software is both verified and signed by Apple. All Secure Enclaves can function independently even if a kernel is compromised and each one contains a unique ID inaccessible to other parts of the system and unknown to Apple, preventing the company or any other third parties from accessing data contained within.

Each Secure Enclave is provisioned during fabrication with its own UID (Unique ID) that is not accessible to other parts of the system and is not known to Apple. When the device starts up, an ephemeral key is created, tangled with its UID, and used to encrypt the Secure Enclave's portion of the device's memory space.

Additionally, data that is saved to the file system by the Secure Enclave is encrypted with a key tangled with the UID and an anti-replay counter.

Fingerprint data collected from Touch ID is stored within the Secure Enclave, which is used to determine a match and then enable a purchase. While the A7 processor collects data from the Touch ID sensor, it is unable to read it because it is encrypted and authenticated with a session key built into Touch ID and the Secure Enclave.

It's encrypted and authenticated with a session key that is negotiated using the device's shared key that is built into the Touch ID sensor and the Secure Enclave. The session key exchange uses AES key wrap- ping with both sides providing a random key that establishes the session key and uses AES-CCM transport encryption.

Along with details on the function and security of the Secure Enclave, the document contains details on Touch ID, most of which have been previously published by Apple in other documents and literature on the feature. It also offers some specifics on the security of fingerprint capturing and a reminder that fingerprint data is accessible only to the Secure Enclave and never sent to Apple or backed up to iTunes or iCloud.

The document's section on Touch ID and the Secure Enclave ends with a detailed description of how both Secure Enclave and Touch ID work together to unlock an iPhone 5s, which is well worth a read for users interested in how the technology functions.

Apple's updated security document has been added as part of a larger redesign of the IT section of its iPhone in Business site, which now features a cleaner design with navigation icons at the top of the page.

Related Forum: iOS 7

Top Rated Comments

Klae17 Avatar
114 months ago
Good timing with the new Samsung S5 Touch-wipe-button. Hey how come no one cares about security when Samsung does it yet when Apple does it we all FLIP?
Score: 34 Votes (Like | Disagree)
taptic Avatar
114 months ago
And the new Galaxy S5, in cooperation with Android, immediately sends your fingerprint to Google headquarters! No hassle guaranteed!
Score: 23 Votes (Like | Disagree)
Nunyabinez Avatar
114 months ago
I would have preferred that they called it the "Fortress of Solitude" rather than the "Secure Enclave."
Score: 20 Votes (Like | Disagree)
DaveN Avatar
114 months ago
Because you're on an Apple-based website?

I posted a question concerning obvious Android fanaticism on the Android Police site some months ago. The amount of hate posts received in response to what was a simple and honest question was astounding. Bottom line is that Apple Fanbois are much more civilized and even tempered than are Fandroids, IMHO.
Score: 12 Votes (Like | Disagree)
seamer Avatar
114 months ago
Good timing with the new Samsung S5 Touch-wipe-button. Hey how come no one cares about security when Samsung does it yet when Apple does it we all FLIP?

Samsung will fix it when Apple shows them how.
Score: 11 Votes (Like | Disagree)
\-V-/ Avatar
114 months ago
Good timing with the new Samsung S5 Touch-wipe-button. Hey how come no one cares about security when Samsung does it yet when Apple does it we all FLIP?
Because you're on an Apple-based website?
Score: 11 Votes (Like | Disagree)

Popular Stories

applefifthavenue

Man Robbed After Buying 300 iPhones From Apple Fifth Avenue

Tuesday November 29, 2022 11:54 am PST by
An unnamed 27-year-old man who purchased 300 iPhones from Apple Fifth Avenue on Monday morning was robbed shortly after leaving the store, according to 1010Wins Radio in New York. He was carrying 300 iPhone 13s in three bags and walking to his car at 1:45 a.m. when another car pulled up next to him. Two men jumped out and demanded that he hand over the bags. Not wanting to hand over 300...
iOS 16

Apple Releases iOS 16.1.2 With Carrier Improvements and Crash Detection Optimizations

Wednesday November 30, 2022 10:09 am PST by
Apple today released iOS 16.1.2, another minor bug fix update that comes one week after the release of iOS 16.1.1 and three weeks after the launch of iOS 16.1, an update that added support for iCloud Shared Photo Library, Matter, Live Activities, and more. The iOS 16.1.2 update can be downloaded on eligible iPhones over-the-air by going to Settings > General > Software Update. According...
app store awards 2021

Apple Announces 2022 App Store Award Winners, Highlighting Best Apps of the Year

Tuesday November 29, 2022 3:10 am PST by
Apple today announced its 2022 App Store Award winners, highlighting the 16 best apps and games selected by Apple's global App Store editorial team. The top apps were chosen by Apple for their quality, innovative technology, creative design, positive cultural impact, and ability to deliver "exceptional experiences." Apple CEO Tim Cook said: This year's App Store Award winners reimagined...
14 vs 16 inch mbp m2 pro and max feature 1

'M2 Max' Geekbench Scores Leak Online, Revealing Rumored Specs and Performance

Wednesday November 30, 2022 2:39 am PST by
Geekbench scores allegedly for the upcoming "M2 Max" chip have surfaced online, offering a closer look at the performance levels and specific details of the forthcoming Apple silicon processor. The Geekbench results, first spotted on Twitter, are for a Mac configuration of with the M2 Max chip, a 12-core CPU, and 96GB of memory. The Mac listed has an identifier "Mac14,6," which could be...
eufy camera

Anker's Eufy Cameras Caught Uploading Content to the Cloud Without User Consent [Updated]

Tuesday November 29, 2022 1:01 pm PST by
Anker's popular Eufy-branded security cameras appear to be sending some data to the cloud, even when cloud storage is disabled and local only storage settings are turned on. The information comes from security consultant Paul Moore, who last week published a video outlining the issue. According to Moore, he purchased a Eufy Doorbell Dual, which was meant to be a device that stored video...
Apple Park View

Elon Musk Meets With Apple CEO Tim Cook Amid Claims of Twitter App Store Dispute [Updated]

Wednesday November 30, 2022 12:43 pm PST by
Twitter CEO Elon Musk today met with Apple CEO Tim Cook at the Apple Park campus in Cupertino, California, according to a tweet shared by Musk this afternoon. Musk thanked Cook for taking him around Apple's headquarters, with no mention of what the two might have discussed. The meeting comes just after Musk on Monday claimed that Apple has "mostly stopped" offering ads on Twitter, and that...
iphone 11 tesla cybertruck close up

Elon Musk Pledges to Build iPhone Rival If Apple Ousts Twitter

Tuesday November 29, 2022 2:48 am PST by
Elon Musk has pledged to offer an "alternative phone" if Apple and Google remove Twitter from their app stores, adding to long-standing rumors about an iPhone rival from Tesla. Modified iPhone 11 Pro in the style of the Tesla Cybertruck, by Caviar. Musk's remark came after being asked about the potential scenario of Twitter being removed from app stores, which could conceivably happen if the...
Cyber Monday Deals Feature 2022

Best Cyber Monday Apple Deals Still Available for AirPods, Apple TV, iPad, and More

Monday November 28, 2022 5:24 am PST by
The Black Friday and Cyber Monday holiday shopping rush is drawing to a close, but there are still some good deals to be had out there. For Apple products, many of the deals you've seen since last week are still available, though some have expired. So for anyone who missed out on Black Friday deals, there's still an opportunity to get some of the year's best prices on many Apple devices. Note: ...
apple music replay 2022 highlight reel cropped

Apple Music Replay 2022 Revamped With 'Highlight Reel' [Updated]

Tuesday November 29, 2022 4:02 am PST by
Apple today rolled out an updated Apple Music Replay experience for 2022, showcasing a new "highlight reel" feature. Subscribe to the MacRumors YouTube channel for more videos. The overhauled experience, which started to be noticed by Apple Music subcribers on Twitter earlier today, puts the new highlight reel feature at the forefront of the Replay webpage, which users are encouraged to...
iPhone 14 Pro Rear Camera

iPhone 15 to Use 'State-of-the-Art' Image Sensor From Sony for Better Low-Light Performance

Monday November 28, 2022 11:00 am PST by
Apple's upcoming iPhone 15 models will be equipped with Sony's newest "state of the art" image sensors, according to a report from Nikkei. Compared to standard sensors, Sony's image sensor doubles the saturation signal in each pixel, allowing it to capture more light to cut down on underexposure and overexposure. Nikkei says that it is able to better photograph a person's face even with...