encdm

Messaging that never asks for your phone number.

You pick a handle, like bryan.42. Your friends add you by it. Nobody hands over a phone number, an email address, or a name to anyone — including the server in the middle.

The cryptography is Signal's own library, not a home-made substitute: post-quantum key agreement, the Double Ratchet, and sealed sender. What is different is identity. Signal is built around a phone number. encdm is built around a handle you invent, which is the part of ICQ worth bringing back.

How it works

A handle, not a number

A nickname and a number: bryan.42. Nobody can hold a bare nickname, so nobody can pose as "bryan". The relay stores only a cryptographic commitment to your handle, so there is no directory to scrape.

Invite only

You join because someone already here gave you an invite. No phone number means no phone bill to keep spammers out, so the social graph does that job instead.

Safety numbers

Every new contact starts marked unverified. Compare a 60-digit safety number with them in person or on a call you already trust. That comparison is what proves the server did not slip its own key in between you.

A recovery phrase

Twenty-four words, shown once when you sign up. They rebuild your account on a new device, with the same identity your contacts already verified. Lose them and the account is gone — there is no reset link, because there is nobody to ask.

What the server can see

Every messenger has a server, and being vague about what it learns is how honest software turns into marketing. Here is the whole list.

Not your messages, or any key that could open them.
Not who sent a message. Messages are sealed: the relay is handed an envelope for a recipient, with no sender on it.
Not your handle, or your contacts' handles — it holds hashes, not names.
That someone deposited a message of roughly some size for a particular account, at a particular time.
Which network address connects, and when — so it knows when an account is online.
Who invited whom, because an invite is signed by its issuer. This one is a real cost, and there is a known fix for it that is not built yet.

Nothing here defeats an adversary watching the whole internet at once and correlating timing. No messenger does. If that is your threat model, plan around it rather than trusting any product's front page — including this one.

Where it stands

Early — not audited

This is a working system built in the open, not a finished product. Judge it accordingly, and do not bet anyone's safety on it yet.

Messaging, contacts, invites, safety numbers, account recovery and a self-hostable relay: working and covered by tests.
An iPhone and Mac app, and a terminal client.
Push notifications: built, with the message decrypted on your phone so the notification service never sees it. Not yet proven on real hardware.
Group chats, voice and video, disappearing messages, attachments: not yet.
No independent security audit. The cryptography is Signal's; the code around it has been reviewed by nobody but its authors.

Getting in

Ask someone who already uses it for an invite code. That is the only way in, by design. An invite is single-use and expires in a week.

The app is not on the App Store and probably never will be: it is licensed under the AGPL, which Apple's terms have long conflicted with. Expect TestFlight or a build you make yourself. There is a terminal client for macOS and Linux too.