Many Mac users experienced app slowdowns during the launch of Big Sur, possibly due to issues with Apple's OCSP service being unable to validate certificates
Even Macs that didn't upgrade to Big Sur had problems. — Mac users today began experiencing unexpected issues …
Ars Technica
Context & Ripple Effects
The slowdowns hit even Macs that never upgraded to Big Sur, pointing to a shared dependency: Apple's OCSP service, which validates Developer ID certificates for Mac apps and sits on the critical path of macOS security. It is not the first time a central Apple credential has stalled apps — in 2015, an expired Mac App Store security certificate left installed apps temporarily unusable.
Follow-up reporting turned the outage into a design critique: a technical deep dive into Apple's OCSP responder argues the service needs more transparency, and days later Apple [[a:960119|stopped logging IP addresses for Developer ID checks and committed to an encrypted protocol]], acknowledging the privacy exposure of phones home that most users never knew were happening.
First-order effects
Mac users saw apps hang or slow to launch during the Big Sur rollout window whenever Apple's OCSP responder failed to validate certificates — including machines still running older macOS versions.
Apple faced a dual problem at once: a reliability failure in a service every signed Mac app depends on, and new scrutiny of what data those routine certificate checks reveal.
Second-order effects
Because the same OCSP dependency spans all macOS versions rather than just Big Sur, Apple is pushed toward resilience changes — caching and fallback behavior — plus the promised encrypted protocol, rather than treating this as a launch-week glitch.
The privacy fallout gives developers and researchers leverage to demand documentation and transparency for gatekeeper infrastructure they are required to trust but cannot inspect or opt out of.
Third-order effects
If platform-critical validation services keep failing or raising privacy concerns while remaining opaque, pressure builds — possibly eventually regulatory — for gatekeepers to expose how their mandatory integrity checks work, mirroring broader debates over platform gatekeeper accountability.
The pattern across 2015 and 2020 suggests Apple's centralized signing and revocation architecture will need local-first resilience by default, shifting macOS security design away from per-launch phone-home dependencies.
The trend: Platform gatekeepers' centralized integrity-checking services are becoming visible single points of failure, forcing both reliability hardening and privacy concessions.
Hey Apple users: If you're now experiencing hangs launching apps on the Mac, I figured out the problem using Little Snitch. It's trustd connecting to https://ocsp.apple.com/ Denying that connection fixes it, because OCSP is a soft failure. (Disconnect internet also fixes.) https:…
😅 Looks like, when apps are launched, Gatekeeper is unable to check their validity over the internet, due to overwhelmed Apple servers. So, uh, let's all hang in there! You got this, Apple devops!
“The issues seemed to begin close to the time when Apple began rolling out the new version of macOS, Big Sur—but it affected users of other versions of macOS, like Catalina and Mojave.” https://arstechnica.com/...
On Big Sur, trustd is in Apple's “ContentFilterExclusionList” ....meaning firewalls can't block it! 😭 Welcome to the future? 😱 https://twitter.com/... https://twitter.com/...
Unimaginable. macOS unable to open any non-Apple application. The joy of Proprietary software. MacOS sends hashes of every executable to Apple server when trustd and syspolicyd cannot do so. The entire macOS stops working. https://twitter.com/...
The huge privacy elephant in the room here is the implication that Apple gets a timestamped call home telling them exactly what program you are running whenever you start one. That's not cricket. There needs to be a way of turning this shite off. https://twitter.com/...
Just upgraded my main machine to Catalina last week, thinking about scheduling my Big Sur upgrade for approximately 12-15 months from now. You guys are clearly more risk tolerant than I am 😂
Holy shit this big sur update must be the worst upgrade experience I have observed. The mac I tried to update to is basically failing to install the update after an awfully slow download and my other mac is now having issues with trustd spinning when I launch apps. The hell apple
You gotta hand it to Apple's third-party dev community to have so many apps Apple-Silicon-native right out of the gate, including beta versions of Microsoft Office. There was always this idea of the ‘app gap’ for Microsoft & its modern efforts, but maybe it's just a developer gap
Speaking of shipping at scale, Apple has now shipped the Apple Silicon versions of its iWork suite, Garageband, Final Cut Pro, Logic, Motion, and Xcode. Compare and contrast with how other platforms have handled their ARM transitions... 🦗🎶 https://twitter.com/...
On two separate Zoom calls we thought the Matrix was glitching because everyone's laptops were crashing simultaneously. No, just Apple: https://twitter.com/...
One more tidbit on Big Sur's design. I know it's not to everyone's tastes, but I think it's fantastic and exactly what the Mac needs for the road ahead. macOS Big Sur: The MacStories Review https://www.macstories.net/... https://twitter.com/...
It fully downloaded and then this happened on iMac Pro. It happened at the same time on another Mac. Server restart on Apples side maybe? https://twitter.com/...