Pair with a contact first
To prove who you are on a call, your phone and theirs need a shared key.
If they say anything else, it is not their phone answering.
Each set of pictures works once and for about five minutes.
Pair with a contact first
To check who is calling, your phone and theirs need a shared key.
Pair with a contact first
A seal can only be checked by a contact whose phone shares a key with yours.
Works in mail, WhatsApp, Signal or SMS. The date is part of the sealed text.
Pair with a contact first
Seals can only be checked for contacts whose phone shares a key with yours.
Pair with a contact first
A printed seal can only be checked by a contact whose phone shares a key with yours.
The code carries your text, the date and a seal. Anyone can read the text in it; only your contact's phone can tell that it is genuine.
This text is too long for one code. Seal only the sensitive part.
Pair with a contact first
Printed seals can only be checked for contacts whose phone shares a key with yours.
After the scan, this phone shows the text your contact really sealed. Compare it with the paper.
Your contacts
The code is not secret, but it must arrive unchanged. Scanning it from your screen is the safest way. Your contact needs your code, and you need theirs.
Backup
A backup holds this phone's own key pair, including the private key, and the names and public keys of your contacts. It is encrypted with your password. A contact's private key never leaves their phone, so it cannot be part of a backup.
Importing replaces this phone's own key and all of its contacts.