General: Forums topic: Privacy & Security Apple Platform Security support document Developer > Security Enabling enhanced security for your app documentation article Creating enhanced security helper extensions documentation article Security Audit Thoughts forums post Cryptography: Forums tags: Security, Apple CryptoKit Security framework documentation Apple CryptoKit framework documentation Common Crypto man pages — For the full list of pages, run: % man -k 3cc For more information about man pages, see Reading UNIX Manual Pages. On Cryptographic Key Formats forums post SecItem attributes for keys forums post CryptoCompatibility sample code Keychain: Forums tags: Security Security > Keychain Items documentation TN3137 On Mac keychain APIs and implementations SecItem Fundamentals forums post SecItem Pitfalls and Best Practices forums post Investigating hard-to-reproduce keychain problems forums post App ID Prefix Change and Keychain Access forums post Smart cards and other secure tokens: Forums tag: CryptoTokenKit CryptoTokenKit framework documentation Mac-specific resources: Forums tags: Security Foundation, Security Interface Security Foundation framework documentation Security Interface framework documentation BSD Privilege Escalation on macOS Related: Networking Resources — This covers high-level network security, including HTTPS and TLS. Network Extension Resources — This covers low-level network security, including VPN and content filters. Code Signing Resources Notarisation Resources Trusted Execution Resources — This includes Gatekeeper. App Sandbox Resources Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

General: Forums topic: Privacy & Security Privacy Resources Security Resources Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

I've come across strange behavior with the userID property on the returned credential from a passkey attestation. When performing a cross-device passkey assertion between iOS and Android by scanning the generated QR code on my iPhone with an Android device the returned credential object contains an empty userID. This does not happen when performing an on device or cross-device assertion using two iPhones. Is this expected behavior, or is there something I'm missing here? I couldn't find any more information on this in the documentation. iOS Version: 26.0.1, Android Version: 13

Hello, I am currently implementing a biometric authentication registration flow using WebAuthn. I am using ASAuthorizationPlatformPublicKeyCredentialRegistrationRequest, and I would like to know if there is a way to hide the "Save to another device" option that appears during the registration process. Specifically, I want to guide users to save the passkey only locally on their device, without prompting them to save it to iCloud Keychain or another device. If there is a way to hide this option or if there is a recommended approach to achieve this, I would greatly appreciate your guidance. Also, if this is not possible due to iOS version or API limitations, I would be grateful if you could share any best practices for limiting user options in this scenario. If anyone has experienced a similar issue, your advice would be very helpful. Thank you in advance.

DTS regularly receives questions about how to preserve keychain items across an App ID change, and so I thought I’d post a comprehensive answer here for the benefit of all. If you have any questions or comments, please start a new thread here on the forums. Put it in the Privacy & Security > General subtopic and tag it with Security. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" App ID Prefix Change and Keychain Access The list of keychain access groups your app can access is determined by three entitlements. For the details, see Sharing Access to Keychain Items Among a Collection of Apps. If your app changes its App ID prefix, this list changes and you’re likely to lose access to existing keychain items. This situation crops up under two circumstances: When you migrate your app from using a unique App ID prefix to using your Team ID as its App ID prefix. When you transfer your app to another team. In both cases you have to plan carefully for this change. If you only learn about the problem after you’ve made the change, consider undoing the change to give you time to come up with a plan before continuing. Note On macOS, the information in this post only applies to the data protection keychain. For more information about the subtleties of the keychain on macOS, see On Mac Keychains. For more about App ID prefix changes, see Technote 2311 Managing Multiple App ID Prefixes and QA1726 Resolving the Potential Loss of Keychain Access warning. Migrate From a Unique App ID Prefix to Your Team ID Historically each app was assigned its own App ID prefix. This is no longer the case. Best practice is for apps to use their Team ID as their App ID prefix. This enables multiple neat features, including keychain item sharing and pasteboard sharing. If you have an app that uses a unique App ID prefix, consider migrating it to use your Team ID. This is a good thing in general, as long as you manage the migration process carefully. Your app’s keychain access group list is built from three entitlements: keychain-access-groups — For more on this, see Keychain Access Groups Entitlement. application-identifier (com.apple.application-identifier on macOS) com.apple.security.application-groups — For more on this, see App Groups Entitlement. Keycahin access groups from the third bullet are call app group identified keychain access groups, or AGI keychain access groups for short. IMPORTANT A macOS app can only use an AGI keychain access group if all of its entitlement claims are validated by a provisioning profile. See App Groups: macOS vs iOS: Working Towards Harmony for more about this concept. Keychain access groups from the first two bullets depend on the App ID prefix. If that changes, you lose access to any keychain items in those groups. WARNING Think carefully before using the keychain to store secrets that are the only way to access irreplaceable user data. While the keychain is very reliable, there are situations where a keychain item can be lost and it’s bad if it takes the user’s data with it. In some cases losing access to keychain items is not a big deal. For example, if your app uses the keychain to manage a single login credential, losing that is likely to be acceptable. The user can recover by logging in again. In other cases losing access to keychain items is unacceptable. For example, your app might manage access to dozens of different servers, each with unique login credentials. Your users will be grumpy if you require them to log in to all those servers again. In such situations you must carefully plan your migration. The key thing to understand is that an app group is tied to your team, not your App ID prefix, and thus your app retains access to AGI keychain access groups across an App ID prefix change. This suggests the following approach: Release a version of your app that moves keychain items from other keychain access groups to an AGI keychain access group. Give your users time to update to this new version, run it, and so move their keychain items. When you’re confident that the bulk of your users have done this, change your App ID prefix. The approach has one obvious caveat: It’s hard to judge how long to wait at step 2. Transfer Your App to Another Team Historically there was no supported way to maintain access to keychain items across an app transfer. That’s no longer the case, but you must still plan the transfer carefully. The overall approach is: Identify an app group ID to transfer. This could be an existing app group ID, but in many cases you’ll want to register a new app group ID solely for this purpose. Use the old team (the transferor) to release a version of your app that moves keychain items from other keychain access groups to the AGI keychain access group for this app group ID. Give your users time to update to this new version, run it, and so move their keychain items. When you’re confident that the bulk of your users have done this, initiate the app transfer. Once that’s complete, transfer the app group ID you selected in step 1. See App Store Connect Help > Transfer an app > Overview of app transfer > Apps using App Groups. Publish an update to your app from the new team (the transferee). When a user installs this version, it will have access to your app group, and hence your keychain items. WARNING Once you transfer the app group, the old team won’t be able to publish a new version of any app that uses this app group. That makes step 1 in the process critical. If you have an existing app group that’s used solely by the app being transferred — for example, an app group that you use to share state between the app and its app extensions — then choosing that app group ID makes sense. On the other hand, choosing the ID of an app group that’s share between this app and some unrelated app, one that’s not being transferred, would be bad, because any updates to that other app will lose access to the app group. There are some other significant caveats: The process doesn’t work for Mac apps because Mac apps that have ever used an app group can’t be transferred. See App Store Connect Help > Transfer an app > App transfer criteria. If and when that changes, you’ll need to choose an iOS-style app group ID for your AGI keychain access group. For more about the difference between iOS- and macOS-style app group IDs, see App Groups: macOS vs iOS: Working Towards Harmony. The current transfer process of app groups exposes a small window where some other team can ‘steal’ your app group ID. We have a bug on file to improve that process (r. 171616887). The process works best when transferring between two teams that are both under the control of the same entity. If that’s not the case, take steps to ensure that the old team transfers the app group in step 5. When you submit the app from the new team (step 6), App Store Connect will warn you about a potential loss of keychain access. That warning is talking about keychain items in normal keychain access groups. Items in an AGI keychain access group will still be accessible as long as you transfer the app group. Alternative Approaches for App Transfer In addition to the technique described in the previous section, there are a some alternative approaches you should at consider: Do nothing Do not transfer your app Get creative Do Nothing In this case the user loses all the secrets that your app stored in the keychain. This may be acceptable for certain apps. For example, if your app uses the keychain to manage a single login credential, losing that is likely to be acceptable. The user can recover by logging in again. Do Not Transfer Another option is to not transfer your app. Instead, ship a new version of the app from the new team and have the old app recommend that the user upgrade. There are a number of advantages to this approach. The first is that there’s absolutely no risk of losing any user data. The two apps are completely independent. The second advantage is that the user can install both apps on their device at the same time. This opens up a variety of potential migration paths. For example, you might ship an update to the old app with an export feature that saves the user’s state, including their secrets, to a suitably encrypted file, and then match that with an import facility on the new app. Finally, this approach offers flexible timing. The user can complete their migration at their leisure. However, there are a bunch of clouds to go with these silver linings: Your users might never migrate to the new app. If this is a paid app, or an app with in-app purchase, the user will have to buy things again. You lose the original app’s history, ratings, reviews, and so on. Get Creative Finally, you could attempt something creative. For example, you might: Publish a new version of the app that supports exporting the user’s state, including the secrets. Tell your users to do this, with a deadline. Transfer the app and then, when the deadline expires, publish the new version with an import feature. Frankly, this isn’t very practical. The problem is with step 2: There’s no good way to get all your users to do the export, and if they don’t do it before the deadline there’s no way to do it after. Test Before You Ship Once you have a new version of your app, with the new App ID prefix, it’s time to test. To run a day-to-day test: On a test device, install the existing version of the app from the App Store. Use the app to generate keychain items as a normal user would. For example, if you store login credentials in the keychain, use the app to save such a credential. In Xcode, run the new version of your app. Check that the keychain items you created in step 2 still work. After you upload this new version to App Store Connect, use TestFlight to run an internal test: On a test device, install the existing version of the app from the App Store. Use the app to generate keychain items as a normal user. For example, if you store login credentials in the keychain, use the app to save such a credential. Use TestFlight to update the app to your new version. Check that the keychain items you created in step 2 still work. Do this before you release the app to your beta testers and then again before releasing it to customers. WARNING These TestFlight test are your last chance to ensure that everything works. If you detect an error at this stage, you still have a chance to fix it. Revision History 2026-04-07 Added the Test Before You Ship section. 2026-03-31 Rewrote the Transfer Your App to Another Team section to describe a new approach for preserving access to keychain items across app transfers. Moved the previous discussion into a new Alternative Approaches for App Transfer section. Clarified that a macOS program can now use an app group as a keychain access group as long as its entitlements are validated. Made numerous editorial changes. 2022-05-17 First posted.

Hello, We are working on integrating app integrity verification into our service application, following Apple's App Attest and DeviceCheck guide. Our server issues a challenge to the client, which then sends the challenge, attestation, and keyId in CBOR format to Apple's App Attest server for verification. However, we are unable to reach both https://attest.apple.com and https://attest.development.apple.com due to network issues. These attempts have been made from both our internal corporate network and mobile hotspot environments. Despite adjusting DNS settings and other configurations, the issue persists. Are there alternative methods or solutions to address this problem? Any recommended network configurations or guidelines to successfully connect to Apple's App Attest servers would be greatly appreciated. Thank you.

Hi Apple Team and Community, We encountered a sudden and widespread failure related to the App Attest service on Friday, July 25, starting at around 9:22 AM UTC. After an extended investigation, our network engineers noted that the size of the attestation objects received from the attestKey call grew in size notably starting at that time. As a result, our firewall began blocking the requests from our app made to our servers with the Base64-encoded attestation objects in the payload, as these requests began triggering our firewall's max request length rule. Could Apple engineers please confirm whether there was any change rolled out by Apple at or around that time that would cause the attestation object size to increase? Can anyone else confirm seeing this? Any insights from Apple or others would be appreciated to ensure continued stability. Thanks!

Hi, I created an app and want to use Google Admob to show ads. I am a little bit confused how exactly tracking, more specifically, the ATT-framework and Google Admob relate to each other. The current work flow is: ATT-permission given -> show google ad mob consent form However, I am confused what I should do if the ATT permission is denied. Can I still show the consent form of google admobs or is that forbidden? If so what do I need to then? Thank you!

we develop extension "Autofill Credential Provider" function for passkey. 1.first step registe passkey 2.second step authenticate with passkey step 1 & step 2 has finished and run success with provideCredentialWithoutUserInteraction. But we want to prepare our interface for use to input password and select passkey what the want. however the func prepareInterfaceToProvideCredential in ASCredentialProviderViewController does call? what i missed? how can i do it?

Hi everyone, I'm developing an iOS app using the AppsFlyer SDK. I understand that starting with iOS 14.5, if a user denies the App Tracking Transparency (ATT) permission, we are not allowed to access the IDFA or perform cross-app tracking. However, I’d like to clarify which in-app events are still legally and technically safe to send when the user denies ATT permission. Specifically, I want to know: Is it acceptable to send events like onboarding_completed, paywall_viewed, subscription_started, subscribe, subscribe_price, or app_opened if they are not linked to IDFA or any form of user tracking? Would sending such internal behavioral events (used purely for SKAdNetwork performance tracking or in-app analytics) violate Apple’s privacy policy if no device identifiers are attached? Additionally, if these events are sent in fully anonymous form (i.e., not associated with IDFA, user ID, email, or any identifiable metadata), does Apple still consider this a privacy concern? In other words, can onboarding_completed, paywall_viewed, subsribe, subscribe_price, etc., be sent in anonymous format without violating ATT policies? Are there any official Apple guidelines or best practices that outline what types of events are considered compliant in the absence of ATT consent? My goal is to remain 100% compliant with Apple’s policies while still analyzing meaningful user behavior to improve the in-app experience. Any clarification or pointers to documentation would be greatly appreciated. Thanks in advance!

https://developer.apple.com/documentation/apptrackingtransparency/attrackingmanager/authorizationstatus/notdetermined Note: Discussion If you call ATTrackingManager.trackingAuthorizationStatus in macOS, the result is always ATTrackingManager.AuthorizationStatus.notDetermined. So, does macOS support getting ATT?

When presenting a cookie banner for GDPR purposes, should ATT precede the cookie banner? It seems that showing a Cookie Banner and then showing the ATT permission prompt afterwards (if a user elects to allow cookies/tracking) would be more appropriate. Related question: Should the “Allow Tracking” toggle for an app in system settings serve as a master switch for any granular tracking that might be managed by a 3rd party Consent Management Platform? If ATT is intended to serve as a master switch for tracking consent, if the ATT prompt is presented before a cookie banner, should the banner even appear if a user declines tracking consent? I’m not finding any good resources that describe this flow in detail and I’m seeing implementations all over the place on this. Help! Thanks!!!

Is there a way (in code or on the OAuth2 server/webpage) to specify the desired window size when using ASWebAuthenticationSession on macOS? I haven't found anything, and we would prefer the window to be narrower. For one of our users, the window is even stretched to the full screen width which looks completely broken…

Hi everyone, I’ve been working on an experimental prototype called FaceBridge that explores whether Secure Enclave–backed biometric authorization can be delegated between macOS and iPhone using only public Apple APIs. The goal of the project was to better understand the architectural boundaries of cross-device trust and approval flows that resemble Apple’s built-in Touch ID / Continuity authorization experiences. FaceBridge implements a local authorization pipeline where: macOS generates a signed authorization request the request is delivered to a trusted nearby iPhone over BLE / Network framework the iPhone verifies sender identity Face ID approval is requested using LocalAuthentication the iPhone signs the approval response using Secure Enclave–backed keys macOS validates the response and unlocks a protected action Security properties currently implemented: • Secure Enclave–backed signing identities per device • cryptographic device pairing and trust persistence • replay protection using nonce + timestamp binding • structured authorization request/response envelopes • signed responder identity verification • trusted-device registry model • local encrypted transport over BLE and local network This is intentionally not attempting to intercept or replace system-level Touch ID dialogs (App Store installs, Keychain prompts, loginwindow, etc.), but instead explores what is possible within application-level authorization boundaries using public APIs only. The project is open source: https://github.com/wesleysfavarin/facebridge Technical architecture write-up: https://medium.com/@wesleysfavarin/facebridge I’m particularly interested in feedback around: • recommended Secure Enclave identity lifecycle patterns • best practices for cross-device trust persistence • LocalAuthentication usage in delegated approval scenarios • whether similar authorization models are expected to become more formally supported across Apple platforms in the future Thanks in advance for any guidance or suggestions.

Hi all, I've on high alert after hearing about the security concerns with npm. Full disclosure, I'm new to computer and network architecture, however, as someone who is on high alert for aplications exfiltrating data or poisioning my on-device machine learning models — I've seen some things I can't fully explain and I'm hoping the community can help. I ran the code odutil show all and I was wondering why certain node names are hidden in my system and when I use the directory utility, I can't use my computer login and password to authenticate to see the users? Am I being locked out of seeing my own system? I'm trying to dig to see if a root kit was installed on my device. Does anyone know what the users and groups in the directory utility are? Who is "nobody" and who is "Unknown user"? I'll probably have a lot more questions about this suspicious files I've seen on my device. Does anyone else's device download machine learning model payloads from the internet without notifying the user (even through a firewall, no startup applications?). I've also tried deleting applications I no longer need anymore and my "system" makes them re-appear.... what?

I can't find any information about why this is happening, nor can I reproduce the 'successful' state on this device. My team needs to understand this behavior, so any insight would be greatly appreciated! The expected behavior: If I delete both apps and reinstall them, attempting to open the second app from my app should trigger the system confirmation dialog. The specifics: I'm using the MSAL library. It navigates the user to the Microsoft Authenticator app and then returns to my app. However, even after resetting the phone and reinstalling both apps, the dialog never shows up (it just opens the app directly). Does anyone know the logic behind how iOS handles these prompts or why it might be persistent even after a reset? Thanks in advance!

I have a very basic binary question around passkeys. Assuming everything is on latest and greatest version with respect to iOS, when user starts creating a passkey in platform-authenticator i.e., iCloudKeyChain (Apple Password Manager) , will iCloudKeyChain create a hardware-bound passkey in secure-enclave i.e., is brand new key-pair created right inside Secure-enclave ? OR will the keypair be created in software i.e., software-bound-passkey ?? i.e., software-bound keypair and store the private-key locally in the device encrypted with a key that is of course created in secure-enclave.

Hello everyone, I'm developing a FIDO2 service using the AuthenticationServices framework. I've run into an issue when a user manually deletes a passkey from their password manager. When this happens, the ASAuthorizationError I get doesn't clearly indicate that the passkey is missing. The error code is 1001, and the localizedDescription is "The operation couldn't be completed. No credentials available for login." The userInfo also contains "NSLocalizedFailureReason": "No credentials available for login." My concern is that these localized strings will change depending on the user's device language, making it unreliable for me to programmatically check for a "no credentials" scenario. Is there a more precise way to determine that the user has no passkey, without relying on localized string values? Thank you for your help.

I’m implementing a macOS Platform SSO extension using ASAuthorizationProviderExtensionAuthorizationRequest. In beginAuthorization, I intercept an OAuth authorize request and call: request.complete(httpAuthorizationHeaders: [ "x-psso-attestation": signedJWT ]) I also tested: request.complete(httpAuthorizationHeaders: [ "Authorization": "Bearer test-value" ]) From extension logs, I can confirm the request is intercepted correctly and the header dictionary passed into complete(httpAuthorizationHeaders:) contains the expected values. However: the header is not visible in browser devtools the header does not appear at the server / reverse proxy So the question is: Does complete(httpAuthorizationHeaders:) support arbitrary custom headers, or only a restricted set of authorization-related headers ? Is there something that I might be missing ? And if custom headers are not supported, is there any supported way for a Platform SSO extension to attach a normal HTTP header to the continued outbound request ?

Hello Apple Team We are integrating App Attest with our backend and seeing a 400 Bad Request response when calling the attestation endpoint. The issue is that the response does not include an X-Request-ID or JSON error payload with id and code, which makes it hard to diagnose. Instead, it only returns a receipt blob. Request Details URL: https://data-development.appattest.apple.com/v1/attestationData Request Headers: Authorization: eyJraWQiOiI0RjVLSzRGV1JaIiwidHlwIjoiSldUIiwiYWxnIjoiRVMyNTYifQ.eyJpc3MiOiJOOVNVR1pNNjdRIiwiZXhwIjoxNzU3MDUxNTYwLCJpYXQiOjE3NTcwNDc5NjB9.MEQCIF236MqPCl6Vexg7RcPUMK8XQeACXogldnpuiNnGQnzgAiBQqASdbJ64g58xfWGpbzY3iohvxBSO5U5ZE3l87JjfmQ Content-Type: application/octet-stream Request Body: (Binary data, logged as [B@59fd7d35) Response Status: 400 Bad Request Response Headers: Date: Fri, 05 Sep 2025 04:52:40 GMT x-b3-traceid: 4c42e18094022424 x-b3-spanid: 4c42e18094022424 Response Body (truncated): "receipt": h'308006092A864886F70D01070... Problem The response does not include X-Request-ID. The response does not include JSON with id or code. Only a receipt blob is returned. Questions Can the x-b3-traceid be used by Apple to trace this failed request internally? Is it expected for some failures to return only a receipt blob without X-Request-ID? How should we interpret this error so we can handle it properly in production? Thanks in advance for your guidance.

I have a question regarding Platform SSO and the use of Secure Enclave–backed keys with biometric policies. If we configure userSecureEnclaveKeyBiometricPolicy with userSecureEnclaveKey, my understanding is that the Secure Enclave key is protected by biometric authentication (e.g., Face ID / Touch ID). In this setup, during a login request that also refreshes the id_token and refresh_token, the assertion is signed using the userSecureEnclaveKey. My question is: Will this signing operation trigger a biometric prompt every time the assertion is generated (i.e., during login/token refresh) ?