Apple Support docs show that unusual mid-production hardware changes were made to its A12, A13, and S5 chips last fall, to update the Secure Storage Component
Hartley Charlton / MacRumors : Tweets: @pandrewhk Tweets: Andrew Pantyukhin / @pandrewhk : Apparently, there was a security reason serious enough to change the production of all A12 and A13 devices in the fall of 2020. Also, TIL, the secure enclave in iPhones *does not* include key storage 🤯 So many questions! https://support.apple.com/... https://twitter.com/...
Context & Ripple Effects
Apple quietly altered the silicon inside shipping iPhones last fall: Support documentation surfaced by Andrew Pantyukhin shows A12, A13, and S5 chips received an updated Secure Storage Component mid-production — a change significant enough that all A12 and A13 devices built from then on carry different key-storage hardware. The discovery also clarified that the Secure Enclave itself does not handle key storage, a detail even seasoned Apple watchers found surprising.
This sits inside Apple's established pattern of treating chip-level security as a physical problem, not just a firmware one: the company runs dedicated Secure Enclave stress testing (its secret testing lab is not linked here, but Federighi's privacy posture has been public since 2019), and its New Product Security team exists precisely to control leaks of the CAD schematics that make such hardware auditable. The later SLAP and FLOP side-channel attacks against M-series and recent A-series chips show why silicon revisions, not just OS patches, keep entering Apple's security playbook.
First-order effects
- Devices already sold before the fall 2020 production switch cannot receive the updated Secure Storage Component — owners of early-run A12/A13 units hold hardware whose key-storage design Apple judged worth a costly mid-cycle respin to replace.
- Apple's manufacturing and supply chain absorbed an unusual mid-generation change across three chips at once, implying the underlying issue was severe enough to justify disrupting mature, high-volume production lines.
Second-order effects
- The used, refurbished, and secondary markets now carry two hardware variants of nominally identical iPhone models with different secure-storage silicon, complicating resale valuation and repair-chain parts matching for A12- and A13-era devices.
- The disclosure hands Apple's rivals a benchmark for security responsiveness: a vendor willing to respin shipping silicon raises expectations for how seriously competitors treat hardware-rooted key protection in their own flagships.
Third-order effects
- If hardware-class vulnerabilities keep surfacing — as they did with SLAP and FLOP — security remediation will increasingly be gated by silicon revision cycles rather than software updates, splitting each product generation into pre-fix and post-fix populations and pressuring vendors to extend patch commitments to the weaker half or accept a two-tier trust base.
- The pattern reinforces vertical integration as a security strategy: only a company controlling both chip design and device assembly can execute a silent mid-production cryptographic change without negotiating through merchant silicon vendors, deepening the structural gap between integrated and assembled phone makers.
The trend: Mobile security is migrating from a software-update cadence to a silicon-revision cadence, where serious key-protection flaws are fixed by respinning chips mid-generation rather than patching them over the air.