How does "Add Phone Number" Work on Wickr?

The "Add Phone Number" feature allows you to optionally associate your phone number with your Wickr ID. It allows people who already have your phone number to find you on Wickr without knowing your Wickr ID. Your phone number is locally encrypted on your device so no one can see your information, but people can still find you by the number that you opt in.

When you use this feature, we disguise your contact information with multiple rounds of salted cryptographic hashing before storing on our servers. This way, you can let your friends find you on Wickr without revealing your contact information to us. If you choose to associate your phone number with your Wickr ID, we use a third party service Twilio to deliver a confirmation SMS to you, but that party will not receive any information about you other than your phone number, and the SMS message itself will contain no information except a confirmation link. 

This feature is optional, and you can always turn it off when you no longer want it active.

To add your phone number, go to the Wickr menu->My Account->Add Phone Number

Landlines, phones with no SMS service, and some ISPs that prevent "bulk messaging" may block the Twilio SMS. Currently, we do not have a secondary verification method to add your phone number. Please let us know at wickr-support@amazon.com if you would like to have a different form of verification to add your phone!

How "Add Phone Number" works in an example where you are adding your number and your Contacts are finding you:

1. You opt to add your number to your account (wickruserA). You add your number and verify with the confirmation text that you do own that phone number.

2. A hashed representation of that phone number (hashedNumber) is added to your account. Now the two ways a new contact in Wickr (wickruserB) can find you; by either:

• searching for your Wickr username in Wickr's "Contacts" screen or
• by having your phone number already in their own address book app on their device then approving any OS "Contacts" permissions on the particular platform for Wickr. 

3. Wickr would then hash (salt to make not plain text; like encryption but one-way: it never needs to be decrypted) wickruserB's address book's phone numbers (including yourNumber). It runs through its check of if any of the hashed phone numbers are a match for any current Wickr account that have an active device registered and have opted to add their number using "Add Phone Number."

4. Wickr will populate and add any Wickr Contacts to wickruserB's Contacts List whose hashed numbers added through "Add Phone Number" are a match for the hashed phone numbers being searched for by your potential Contacts, and whose accounts are active. In this way, wickruserB is able to contact wickruserA by knowing only their phone number, and not their Wickr ID (username).