Restrict access to individual contacts on a per-app basis
Summary
Offer an option so that the access to saved contacts can be limited to an individual sub-set of contacts for each app.
Description
Currently, Android (and therefore /e/OS) only has a "all or nothing" option for contacts: An app is either granted read & write access to all contacts or to none. Popular apps like WhatsApp usually upload all contacts to a server e.g. to find acquaintances of the user that also use the app in question. However, this usually also involves a large number of contacts that do not use the app at all. This is problematic from a privacy point of view as it e.g. allows to know the whole social circle of someone.
iOS 18 and GrapheneOS offer solutions to limit the set of contacts an individual app can access. A corresponding solution in /e/OS would be desirable.
Who will use this new feature?
Most /e/OS users who install popular apps like WhatsApp that upload all contacts to their respective server
Why these users would like to use this feature?
This feature would be useful for almost all /e/OS users as they can install and use certain apps like WhatsApp without exposing all of their contacts to the app publisher. This would increase the privacy of all users.
Examples
A user can install a messaging app like WhatsApp and only allow access to the contacts for whom the user knows that they already use the app. The user can then directly write to these contacts via the messaging app. However, other contacts that do not use the messaging app are unkown to the app publisher.
Reflection
The idea for this feature is discussed in this /e/OS forum thread.
Additional links:
- Description of the iOS 18 feature: https://www.digitaltrends.com/mobile/ios-18-has-a-big-privacy-change-contact-sync-what-it-means-for-you/
- Description of the GrapheneOS feature: https://grapheneos.org/usage#contact-scopes
- Part of the corresponding code changes on GitHub: https://github.com/GrapheneOS/platform_frameworks_base/commit/e86cd41c2965067cc1e9d531933ca134c16270c0
- Description of a similar feature proposal on this GitLab: #389 (closed)
- Similar feature requests for upstream Android:
Validation
- Install a third-party contacts app like Fossify Contacts. Grant access to (e.g.) only the first two contacts on the smartphone. Open the app. It shows only the first two contacts. Grant access to more contacts and restart the app. It now shows (only) the allowed contacts, but not the other ones.
- Install WhatsApp. Make sure that two contacts are saved on the phone that also use WhatsApp, but grant WhatsApp only access to one of the contacts. Open WhatsApp and finish the initial setup. Select the entry in WhatsApp to start a new chat. Only the contact for which access has been granted is visible. Repeat this with more contacts that use WhatsApp: Only the contacts to which access has been granted are visible.