Sign in with Apple
Fast, easy sign-in with privacy built inNovember 2019

Overview
Sign in with Apple is a new service from Apple that allows users to sign in toapps and websites quickly and easily using the Apple IDs they already have.
It’s a privacy-friendly alternative to other single sign-on solutions and provides
users with the convenience of one-tap sign-in combined with superior security
and improved privacy and control over their personal information.
Social login services from major internet brands are convenient to use, but thisconvenience can come at the cost of the user’s privacy. It’s common for users
to be asked to share their name, email address, friends list, and other profile
information when setting up an account with a new app. And the data sharing
may not stop there. The persistent identity provided by a social login can becombined with data from tracking pixels and other analytics inside of appsthat track the user’s browsing habits, clicks, searches, and more, without theirknowledge. This collected data amounts to a comprehensive profile of theuser’s behavior and preferences that may be shared not only with the app theuser is engaging with, but also with the company the user has trusted with theiridentity. And of course, personal data collected in this way can leak, be stolen,
and be vulnerable to misuse by any third parties that gain access to it.
Apple believes that great user experiences and great privacy can go hand-inhand, and that users should be able to enjoy the convenience and security of
one-tap sign-in without compromising their privacy. With that principle in mind,
Sign in with Apple has been built from the ground up to limit the amount ofinformation that users are required to share, and to provide them with the peaceof mind that Apple will not track them as they interact with their apps.
For developers, Sign in with Apple is an opportunity to engage new users
quickly and easily. Sign in with Apple provides a superior, one-tap experiencefor starting an account, superior security with two-factor authentication, andincludes a new tool to help fight fraud and scripted account creation.
A simple set of APIs allows any developer to add Sign in with Apple to their app
or website. It works on iOS, iPadOS, macOS, watchOS, and tvOS, as well as on
the web and other platforms, so developers can implement it anywhere they
deploy their apps, including on Android or Windows.

Fast, easy account setup
When it’s time to set up an account and sign in to a participating app or website,
the user can simply look for the “Sign in with Apple” button and give it a tap.

Sign in with Apple | November 20192

A native sheet appears that allows the user to review relevant information andthen tap Continue and complete a simple Apple-approved authentication likeFace ID or Touch ID to sign in automatically. Users can sign in to a new app
without filling out any forms or sharing any personal information at all. Just aunique, stable identifier that allows the user to sign in again anytime using theApple ID they already have.

Sign in with a tap
Once an Apple ID–backed account is established with the developer, users
can sign in to the app again anytime they like by tapping the Sign in with Apple
button again and providing a quick Apple-approved authentication such as
Face ID or Touch ID. This seamless sign-in to apps is available on any device
where the user is signed in to iCloud with their Apple ID.

Sign in with Apple | November 20193

Signing in on the web and other platforms
Users can also use Sign in with Apple to sign in to websites using Safari,
Chrome, Firefox, Edge, and other browsers, and to sign in to apps on otherplatforms such as Android or Windows.
When a user is using Safari on a Mac or any WebKit browser on iOS or iPadOS,
a sheet drops down from the navigation bar that allows the user to sign inquickly and easily just as if they were in a native app.

When using other browsers or signing in on a non-Apple platform, the user
will need to enter their Apple ID and password into a secure, Apple-hosted
web page to identify themselves and complete the sign-in. Otherwise, theexperience is the same.

Sign in with Apple | November 20194

Hide My EmailSome apps and websites require a bit more information to set up a personalizedaccount for their users. To accommodate this, Sign in with Apple allows
developers to request a name and email address if required and will prepopulate the requested information from the user’s Apple ID account directly
to the Sign in with Apple sheet, so the user can review and approve sharing theinformation with the developer before proceeding. The user can edit their firstand last name as needed, and when it comes to their email address, they havea choice: They can choose to share any verified email address on file in theirApple ID account, or choose Hide My Email to share a unique, private relay
email address instead. Any email sent by the developer to this address will be
forwarded directly to the user’s verified inbox. This allows the user to receive
useful email messages from the developer, and even respond to messages
directly, without revealing their personal email address.

Relay email address
When a user chooses Hide My Email, aprivate relay email address is createdsimilar to the example below:
56tr9k16b2@privaterelay.appleid.com
Any email messages sent to this address
will be forwarded to the user’s verified
email inbox.

Each relay address is unique to the user and to the developer, so it can’t be
used for tracking a user across apps or matching with other profile informationtied to a personal email address.
To enable sending messages through the private relay service, developers
must register the domains and email addresses they use to send messages
to their customers. This information allows Apple to forward emails from thedeveloper directly to the participating user’s personal inbox and handle direct
replies without exposing the user’s real email address. It also means that only
the developer that controls the registered domains can send emails to the relay
email address. The mail system employs standard DKIM, DMARC, and SPF
policies to ensure all sending domains are legitimate.
Apple does not read or process any of the content of the email messages thatpass through the relay service, except to perform industry-standard spam
filtering that is required to maintain Apple’s status as a trusted email provider.
All email messages are deleted from Apple’s servers once they are delivered
to the user, usually in a matter of seconds.

Sign in with Apple | November 20195

The user can turn off their relay address for a given developer at any time.
When they do, emails will bounce back to the developer the same way theywould if the user’s email account had been shut down. The user can decideto provide their real personal email address directly to the developer anytime
they like.

No tracking
Perhaps the most significant privacy benefit of using Sign in with Apple isthat Apple does not participate in tracking or profiling users and does not seek
to profit from users’ personal data. Apple will not track users as they engage
with their favorite apps and websites, or gather insights about developer’s
businesses in the process. In fact, Sign in with Apple has been built from theground up to limit the amount of information Apple can access or store about
the user’s sign-in behavior.
When a user engages with a new app using Sign in with Apple, Apple generates
a unique token for the user/developer pair and stores the email address thatthe user shares with the developer. This allows Apple to manage secureauthentication anytime the user needs to sign in, and allows the user to view
and manage their relevant account details. Any subsequent visits to an app canbe handled on device without sharing any additional information with Apple.
Developers can call a local refresh API (getCredentialsState) to confirm thatthe user is still securely signed in to iCloud on the device and allow the user tocontinue using the app seamlessly without ever reaching out to Apple’s servers
or sharing any additional information.
If an explicit sign-in is required to continue using an app—for example, to sign
in to a financial services app with a limited session length—the developer willcall an authentication request API (ASAuthorizationAppleIDRequest) that
returns a token from Apple’s servers to allow the user to quickly sign in again.
In this case, Apple receives basic information about the sign-in event, including
the IP address and the Apple ID being used, but deletes this information aftera maximum of 30 days.
When signing in using a non-Apple web browser or an app running on anotherplatform, Apple is not able to provide an equivalent to the local refresh API.
Therefore, developers will need to make a fresh authentication request eachtime the user needs to sign in. The same token will be returned from Apple’s
servers and the same 30-day data deletion policy applies.
This is the extent of information that Apple collects regarding users’ activity
as they use Sign in with Apple. Apple does not provide any tracking tools todevelopers or receive data from any analytics or advertising tools that might
be employed by any particular app. As a result, users can take advantage ofthe convenience of Sign in with Apple with the peace of mind that Apple is
not tracking or profiling them.

Sign in with Apple | November 20196

Secured with two-factor authentication
Two-factor authentication
Two-factor authentication is an extra
layer of security for your Apple ID,
designed to ensure that you’re the only
person who can access your account,even if someone knows your password.
Whenever you sign in to a new device forthe first time, you are required to provide
your password and a six-digit verification
code from one of your other trusted
devices, or a trusted phone number.
More detail can be found at:https://support.apple.com/kb/HT204915

To provide superior security, Sign in with Apple requires the user’s Apple ID to
be protected with two-factor authentication. This not only protects the user’s
Apple ID from fraud and other security threats, but also protects the accounts
and data that users create in apps they use with their Apple ID. Developers that
implement Sign in with Apple get this extra security automatically. Instead ofbuilding an elaborate two-factor authentication system themselves, they canemploy Sign in with Apple to take care of it for them.
As of September 2019, more than 75 percent of all active Apple IDs had alreadybeen protected with two-factor authentication and this number continues togrow, so the vast majority of users can take advantage of Sign in with Apple
without any additional requirements. Furthermore, since users are persistently
and securely signed in on their devices, they will not receive any additionalverification prompts when signing in to apps from an Apple device. A simple
Face ID or Touch ID verification takes care of it. On non-Apple browsers andother platforms, the user will need to provide their Apple ID, password, and averification code on their first sign-in from a new device or browser. However,if they wish, they can skip the verification code step for 30 days by choosing
to trust the browser they are using.

Real User indicator for anti-fraud
On-device intelligenceApple uses machine learning to help
make the user’s experience with theirdevice and apps more intelligent andpersonalized. It’s used for image andscene recognition in Photos, predictive
text in keyboards, and more. Sign in withApple utilizes on-device intelligence tohelp determine that the user is a real
person, without having to store or
analyze any sensitive personal
information on Apple servers.

In addition to helping developers engage new customers in an easy andprivacy-friendly way, Apple is committed to reducing fraud, scripted accountcreation, and other bad behavior that can have a negative impact on developers
and their businesses. Apple actively controls fraud on its own systems and nowoffers a simple tool called the Real User indicator to assist apps and services
that adopt Sign in with Apple.
The Real User indicator is a binary score that indicates whether Apple isconfident the user setting up the account is a real person without any signs offraud on their Apple ID account, or if there is insufficient information to make adetermination.
Apple has gone to great lengths to ensure the indicator is calculated in a
privacy-preserving manner. First, on-device machine learning (ML) is employedto measure if the device the account is originating from is being used in a way
that’s consistent with ordinary, everyday behavior such as moving from place
to place, sending messages, receiving emails, or taking photos. This analysis
yields a tamper-proof numerical score that is sent to Apple indicating a level ofconfidence that the device is being used by a real person. The score cannot bereverse-engineered by Apple to reveal any personal information, and none of
the specific inputs to the ML models ever leaves the user’s device.
The device score is then combined with select information on recent accountactivity. The sum of this information is abstracted into the binary Real User
indicator that is passed to the developer at account setup time. Developers canSign in with Apple | November 20197

incorporate this information into any existing anti-fraud systems they currently
use to help make determinations about how to handle a new customer.
When a developer receives the indication that the account is owned by a realuser, they can confidently allow the user to proceed into their app experience
without requiring additional verification steps. If the developer receives an“unknown” score, the developer can use the same supplementary verification
methods they would normally use for a new account. An unknown score does
not necessarily mean that the account is fraudulent or fake, it simply meansthat there is not enough information available to provide a Real User assertion.

Managing the apps that use your Apple ID
At any time, the user can visit their Apple ID account settings on their device
or sign in to https://appleid.apple.com to view all the apps that are using
their Apple ID to authenticate. They can review the information they originallyshared with each app, view the app’s privacy policy, turn off their private relay
email address for the app if they wish, or stop using their Apple ID with theapp entirely.

Fast, easy sign-in that respects users’ privacy
Having a fast, easy, and secure way to sign in to apps and services is essential
for both users and app developers. Sign in with Apple was purpose-built toallow for rapid, friction-free on-boarding to new apps, while respecting users’
privacy and keeping them in control of their personal information.
Sharing information with apps and services is a natural part of engaging anddoing business. Sign in with Apple provides users with more transparency andcontrol when setting up new accounts and using their favorite apps.
Sign in with Apple will be required in any app in the App Store that uses
third-party sign-in services to set up and authenticate user accounts. This will
help ensure that users always have the choice to use their Apple ID and takeadvantage of Apple’s privacy policies whenever they are also offered the option
to use a social login service.

Sign in with Apple | November 20198Details on this requirement can be found in Apple’s App Store ReviewGuidelines located at https://developer.apple.com/app-store/review/guidelines.
Developers can also visit https://developer.apple.com/sign-in-with-apple fordetailed information on how to implement Sign in with Apple in their apps andwebsites.

© 2019 Apple Inc. All rights reserved. Apple, the Apple logo, Face ID, Mac, macOS, Safari, Touch ID, and watchOS
are trademarks of Apple Inc., registered in the U.S. and other countries. iPadOS and tvOS are trademarks of Apple Inc.
App Store and iCloud are service marks of Apple Inc., registered in the U.S. and other countries. IOS is a trademark or
registered trademark of Cisco in the U.S. and other countries and is used under license. Other product and company
names mentioned herein may be trademarks of their respective companies. Product specifications are subject tochange without notice. This material is provided for information purposes only; Apple assumes no liability related toits use. November 2019

Sign in with Apple | November 20199