ian
April 29, 2026, 8:36am
2
TL;DR Print the invite QR and minimized i.delta.chat link on your business card or on a regular sheet of paper cut up to small slices. The recipient of such a card can either scan or type it in at home. No theoretical decentralized alternative could provide you a way to remember it and spell it out over the phone, because any such scheme would preferably require sharing at least 256 bits of entropy (43 random characters in base64 or 52 in more “easily” remembered base32). Even a toy scheme would require 128 bits that is already out of reach.
See also problems with centralized alternatives and other issues this is a duplicate of:
Yes, you can cut off the name, but your peer will see your name again after joining. So, you should preferably pick a name that is not compromising for you in the first place when creating a throw away profile for invitations.
Shortening the invite link would defeat the whole purpose of providing cryptographic material out of band.
Centralized usernames would defeat the purpose of the decentralized nature of DC, open up a centralized actor to metadata collection and could MITM and deny people …
In that case, this is a duplicate of the following:
@jase Your phrasing seems overly verbose and vague, but let me see whether I understand what you want:
I have joined a public group of untrustworthy strangers. Then one of the participants started harassing and stalking me. What should I do?
You should delete the profile, create a new one and join the group with that (or just join other groups instead). In general, you should only participate in untrustworthy groups and contact untrustworthy individuals with a throw-away profile.
The threat…
Scanning a QRcode that contains a vcf with all required properties (version, email, fn, key, rev) results in DC trying to initiate contact through unencrypted plaintext email. This is blocked by chatmail.
However, if i scan the QR_code with an external barcode reader app, save it to a file, send the file to the saved note chat in DC and then click on the uploaded file (contact button), it does initiate encryption correctly!
I couldn’t find a duplicate for this issue, but some are loosely relat…
hi,
how can I invite someone far away from my computer. He can’t scan the QR-code on my screen!
Same problem: how can I verify someone far away.
By the way: I started a verified group with 2 members without scanning the QR-code. And I can chat!
Thanks and greetings
Gert
The advantages:
works offline (for people who do not have a mobile data flatrate)
The QR codes could even be printed on visiting cards or similar
The disadvantages:
Actually only one direction is verified (if Alice scans Bob’s code, A can be sure that she chats with B. - But Eve could scan B’s code and do as if she was A without B noticing). So, B can’t be able to add A to a verified group.
B could ask A whether the verification worked and then be sure that he chats with A but DC won…
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