How it works

Last updated 24 August 2026

Every claim below is either true of the software today or listed at the bottom as something that is not. We would rather be dull than be caught.

The server cannot read your messages

Text, formatting, photos, videos and files are encrypted on the device that sends them and decrypted on the devices that receive them, using MLS — RFC 9420, the same standard the IETF settled on for group messaging. The keys are made on your phone and never leave it. What sits in our database is a run of bytes; there is no key anywhere on the server that turns it back into a sentence, and nothing we could be compelled to hand over would.

What the server does see, because delivering a message requires it: that an account sent something to another account, when, how large it was, and the names and phone numbers accounts registered with. Encryption hides what you said. It does not hide that you spoke, and anyone who tells you otherwise is selling something.

The notification carries nothing

A push tells your phone that something arrived and how many are unread. Not the text, not who sent it — the server could not put them in even if it wanted to, because it cannot read either. Your device decrypts the message and writes the notification itself.

Nobody can look you up

There is no directory, no search for people, no suggested contacts, and no way to discover an account by wandering. You get in on an invitation, and afterwards you are reachable by a number somebody already has. We send no SMS and ask for no e-mail: a code from us is minted by hand and given to one person.

The way back is yours alone

When your account is made, the device makes six words and shows them to you once. They are the only way back if the phone is lost. The server is told a one-way derivation of them and nothing else — enough to recognise you when you type them, useless for signing in as you, and useless for reading anything. We could not give you the words back if you asked, which is the point of holding them this way.

No advertising, no analytics, no third parties

No profile of you is assembled and nothing is sold to anyone. The app carries no analytics and no crash telemetry. The only outside parties in the path are Apple and Google, who deliver the push that wakes the app — and what they deliver says nothing.

You can check all of this

The clients are forks of the Telegram apps and the server is our own, all of it open. Every sentence on this page is a claim about code somebody else can read. That is deliberate: a private messenger whose workings are secret is asking for exactly the trust it says you should not have to give.

Your own server

ice9 talks to one server, and the app asks which on its first screen. Ours is filled in and most people will keep it; anything else you type is checked before it is stored. Putting one up on a machine of your own is one command and about ten minutes. Everybody in a conversation has to be on the same server — accounts, messages and keys belong to the server that issued them, and there is no bridge between one and another.

What is not true yet

These are the work between here and a first release, and neither is finished. They are listed because a page that only says the good half is a page that has to be rewritten the first time somebody asks a hard question.

• A delivered message stays on the server. Until somebody deletes it or the account goes — the ordinary behaviour of every messenger, and encrypted throughout, but it is a copy that outlives its delivery. What is coming is not a change to this: it is a mode a conversation can be put into, where the copy goes once every authorised device has acknowledged it. Off by default, because it changes what a newly signed-in device can expect to find, and that is a thing to choose rather than to discover.
• Guessing the phrase will cost time. Six words from a list of 2048 is about 2⁶⁶ combinations, which no person will ever type through. A machine does not type. So the server will allow a small number of attempts per account per hour, the wait will grow with each failure instead of resetting, and the count will survive a restart of the server, so it cannot be cleared by knocking it over.
• Much of what a Telegram app can do is switched off here. Calls, channels, stories, reactions, sticker packs, folders, archive, chat themes, bots, translation, scheduled messages and video chats: none of these has a server side yet, and each is off in the app rather than half-working. What is on is what this page describes: people, groups, text, pictures, files, replies, forwards, notifications.
• The server is still trusted for two things. It cannot read a message, but it can still see who talks to whom, and what the traffic looks like on the wire is still recognisable. Both are open work, written down in the repository, and neither is finished.