Services you or your agents use. Ask them to accept Atum instead of a face scan or an ID: one tap gives you a ready message. Free credits and free tiers first: that’s where agents already take what’s meant for people.
Atum shows a service only that a real, long-lived phone is behind you. No name, no face, no documents.
When an epoch closes, the phone sends Atum a short signed summary of that minute. The raw readings stay on the phone.
Each epoch your phone signs carries the fingerprint of your previous signed epoch. Together they form your own chain.
Every 10 minutes, on the clock, Atum closes a batch: it takes every epoch it has accepted since the last batch, from all phones, and builds one tree from their fingerprints. Each epoch is one leaf. The top of the tree is the root. A few minutes later Atum’s contract puts the root on the blockchain.
When two Atum phones meet, each sends a hello signed with its key. Each hello carries the fingerprint of that phone’s chain up to that moment.
A gap means there is no signed epoch for those minutes. It doesn’t tell why: the phone may not have been collecting, or it collected and hasn’t signed yet.
Every epoch with the ↗ arrow is already on the blockchain. The arrow opens it in Atum’s explorer.
Trust is the first thing someone sees when they scan your passport. It shows how much life your passport holds: signed on your phone, unbroken, and lived over time.
Your key lives in this phone’s security chip and can’t leave it. That is what makes the passport hard to fake, and it means a passport can’t move with you.
Counted from the phone’s own sensors, with no location. We are still tuning them, so treat them as estimates.
atum:7c1e·a4f2·09bd·94af
When you started Atum, the security chip of this iPhone created two keys. The private key never leaves the chip and signs every minute. The public key is kept by Atum, so anyone can check those signatures.
Your passport number is a short fingerprint of the public key. atum: only says it is an Atum number.
Your iPhone has a separate security chip, the Secure Enclave. It is the same chip that protects Face ID and Apple Pay.
When you started Atum, the chip created a private key for your passport. The key was born inside the chip and can never be read out of it: not by Atum, other apps or even you.
Every minute the chip signs your epoch with this key. The signature proves this phone signed the minute and was not changed afterwards.
Your phone signs every minute. A signature proves which phone wrote the minute, but not when: on its own it could have been made later. The blockchain fixes the time, and nobody owns it, not even Atum.
Atum needs only Bluetooth and Motion. Atum never asks for location, microphone or contacts. Tap a row to open iOS Settings.
In an encounter a nearby Atum phone signs your epoch and you sign theirs.
There is no account and no sign-in. Deleting the passport removes the key and everything Atum keeps on this iPhone. Epochs already uploaded stay with Atum under the old key. With the key gone, nobody can sign as that passport again.
The key and everything Atum keeps on this phone are deleted. Epochs already uploaded stay with Atum under the old key, and no one can sign as this passport again. Epochs not uploaded yet are lost.
Send them this, or post it where they’ll see it. The more people ask, the sooner they add Atum.