Track "Contact Auth UI" (Public Key Fingerprint Verification, eg QR Code Scanning)

[maltfield]

This is a request to add a new row (called Contact Auth UI) to the spreadsheet that tracks whether or not an app has some UI for users to to verify their contacts' authenticity.

Why?

The purpose of this is to authenticate the contact to make sure that the contact is who they say they are (and not someone pretending to be them or a MITM attacker that's relaying messages)

Examples

This is typically implemented by having one user scan a QR code of their contact's public key (eg Threema).

Other apps may implement this by displaying a fingerprint or a series of words.