If you’ve ever worried about users faking requests to your backend, or wondered how to make sure those API calls are really coming from your actual iOS app — not some cloned or jailbroken copy — then Apple’s App Attest framework is worth knowing about.
App Attest is part of Apple’s DeviceCheck service, and it’s basically Apple’s way of helping you prove that a request to your server is from a real unmodified instance of your app, running on a real Apple device.
Let’s break that down.
The Problem It Solves
Here’s the common story: you build a mobile app that talks to your backend API. The app needs to authenticate somehow, so you might include an API key or secret. But as any experienced mobile dev will tell you, anything shipped inside an app can be extracted. Tools like class-dump, proxy sniffers, or simple decompilers make it trivial for a motivated user (or bot) to rip that key out and start hitting your backend directly — bypassing your app altogether.
That’s not good. Your backend now can’t tell a real app from a fake one.
App Attest aims to fix that. It lets your app prove to your server that it’s running on legitimate Apple hardware, installed from the App Store, and hasn’t been tampered with. That means that your server will be able to deny requests from clients that don’t pass this test.
How It Works (At a High Level)
When your app first runs, it uses Apple’s DCAppAttestService API to generate a key pair on the device’s Secure Enclave — the same secure hardware that stores Face ID and Touch ID data.
That key never leaves the device. Apple signs the public part of it, giving you an “attestation” — basically a proof that the key came from a real, untampered app on a valid device. You then send that attestation to your server, which can verify it against Apple’s attestation service.
Once verified, your server can associate that key with a user session or device record. From then on, your app can sign requests with that key, and your server can verify those signatures to ensure each call is genuine.
What It Looks Like in Practice
Let’s imagine the basic flow between your iOS app and your backend:
-
Generate the key:
Your app callsDCAppAttestService.shared.generateKey()to create a new attestation key. -
Get the attestation:
Next, the app callsattestKey(_:clientDataHash:)to ask Apple to sign that key, proving it’s legit. -
Send it to your server:
The app sends the attestation data to your backend. -
Verify it with Apple:
Your server takes that data and verifies it via Apple’s attestation verification endpoint (or using Apple’s cryptographic materials, depending on your setup). -
Store and trust:
Once verified, your server stores the key’s public identifier. From now on, the app can use that key to sign requests, and your backend can check the signature to ensure the request came from your actual app.
It’s like a built-in “hardware handshake” between your app and your backend.
There’s an Easier Way
For most mobile developers, setting up complex AI gateways, mutual TLS, or hardware-backed authentication can feel like overkill. But if you’re using something like Gate/AI, App Attestation is built-in. Gate/AI handles your secure service integrations for you, including App Attestation. You get serious security without the pain of traditional infrastructure.
Final Thoughts
App Attest won’t magically solve all security problems — you’ll still want to handle authentication, rate limiting, and encryption. But if you’re shipping an app that talks to any kind of backend API, it’s worth implementing. It’s Apple’s way of giving you a cryptographic “seal of authenticity” for your app.
And as mobile devs, anything that helps us spend less time worrying about keys and hacks — and more time building cool stuff — is worth taking seriously.