Discover mutuals

[irvan-putra]

Expected behavior

1. When i first sign up for DeltaChat or any other time, i can initiate mutuals discovery. This is when I allow DeltaChat to check my contacts if they are already in DeltaChat

2. I will be told if my contact is finally in DeltaChat

I know there is a security & privacy concern about this so I will refer to Bluesky trying their best to solve that concern by hashing the contact:

The blog post: Find Your Friends on Bluesky - Bluesky

The RFC: Request For Comments: A secure contact import scheme for social networks | Bluesky

Of course Bluesky can do that because it is checking phone number and centralized service, so this proposal may be rejected for that reason.

Actual behavior

I only know if my contact in DeltaChat if they told me directly

Example Images

From Bluesky:

From Telegram and article trying to fix the noises: https://medium.com/@bedmutha.riddhi/ux-case-study-solving-contact-joined-telegram-chat-feature-of-telegram-b56effd599e8

[ian]

I moved this comment to its separate issue:

Probe existing email contacts upon installation for easy onboarding

A user would install DC On first start, DC would scan for email addresses (along with fingerprints and public keys) in the device address book, the IMAP folder of the DC accounts of the user and possible further “external” IMAP accounts (not otherwise added to DC). If any entry has an email address not known to DC, DC would send a probe email to it. If DC on the other side accepts this contact and proceeds with encrypted communication, extend the device address book entry with the public key an…

[irvan-putra]

Probing email for all email address in address book not yet DeltaChat is actually different idea.

This topic is actually to discover if someone else already in DeltaChat with both me and my contacts registering our intent to discover mutuals to a service and that service save our telltale like phone numbers or email address.

[ian]

In that case, this is a duplicate of the following:

Contact-Lookup Service

Hello there, please forgive me if this has already been widely discussed but I didn’t see it anywhere: I’d like to propose a lookup server (or actually confirmation server). Motivation I want a “phone book” in DeltaChat that shows me who I can contact, who will not just get an email but also “speak DeltaChat” When inspecting a contact on Android (surly on iOS too) I get hints what messengers that contact is using. That is how I usually decide how to contact another person. And I’d like t…

Search Server Adress Book

A really nice feature, wich would separate DC from other Messengers, could be the function to pull matching emails from the server address book on contact search. I think this would be a huge benefit for companies and organizations and you can’t do on Whatsapp AFAIK Imap don’t support this (only exchange) but some email Clients just using LDAP or AD instead: https://serverfault.com/questions/235447/getting-contact-list-from-imap-server So this could be the way to go. Maybe allow it to be conf…

Search contacts by phone number

Introduction Yep, you heard it right. I know it’s a wild idea. But with Delta Chat becoming more and more normie-friendly (e.g. instant onboarding) I thought I’d shoot my shot. Why it’s important We know that practically every messenger including Signal uses phone numbers to look for contacts. All family members usually have each other’s phone number, unlike, let’s say, Instagram or Snapchat or email address. So when you aren’t, want to connect with you on a messenger, all you have to do is …

QuicksyServer: phone number directory lookup for email adresses?

Some people seem to want address book matching, and Quicksy is a derivate of the Conversations XMPP App providing that feature. They also published the server code: As jabber IDs look the same as email addresses, there might even only be a patch needed when storing both on a shared server…

Welche Kontakte nutzen Delta Chat

Hallo zusammen, gibt es eine Einstellung, die anzeigt, welche meiner Kontakte bereits die Delta Chat App nutzt - also Delta Chat nicht als Email-Programm, sondern als Messenger? Besten Dank Gerhard

[irvan-putra]

Thanks, there is one that i miss, so i have replied there:

Search contacts by phone number

So i only know there is already this proposal even though i have created new one: Discover mutuals The cost is something to consider. It is possible if the user actually want to pay, then maybe it is separate bot/app than DeltaChat default one, but then we won’t get matching numbers…

[ian]

Good catch. Note that if you write the link on its own line, a preview will be generated for it inline.

[irvan-putra]

Thanks, that’s neat trick!

If there is any other feedback, please feel free to reply.

I think my proof of concept will be a separate app for discovery of mutuals on other protocols/networks, not only DeltaChat, since end users will need to pay for the SMS or email verification, and keeping the service up, so generalizing this hopefully will allow adoption.

I have a feeling someone already does that kind of app though, but maybe not with DeltaChat as one of the “I am currently using this app”.

[ian]

There was a proprietary service for this in the past:

Keybase

[adbenitez]

@irvan-putra

I know there is a security & privacy concern about this so I will refer to Bluesky trying their best to solve that concern by hashing the contact:

hashing doesn’t solve the problem, it is not only about server storing phone numbers, but anyone being able to iterate over phone numbers, generate hash and ask the server for the contact, basically any contact discovery is at the same time an anti-feature, there are enough of such messengers out there, it is better if Delta Chat tries to cover the other need:

a safe messenger for family and kids where no one can discover your family members and scam them, do fishing or manipulate children, ex. ask for pictures etc.

also no public groups or channels so kids can’t end up discovering inappropriate content

so for the time being these features are not wanted in Delta Chat, this is not a social network but a private messenger

[irvan-putra]

yeah, i agree, Bluesky can do that because they are public social media.

[irvan-putra]

open source alternative:

Keyoxide

[link2xt]

@adbenitez

hashing doesn’t solve the problem, it is not only about server storing phone numbers, but anyone being able to iterate over phone numbers, generate hash and ask the server for the contact

Follow the links, this is addressed in Bluesky RFC and blog post.

[adbenitez]

still wouldn’t solve the problem of needing a trusted central server with state/metadata tho