Company

About 3NUM Labs

3NUM Labs is the engineering company behind ATSMS, the open standard for private phone calls and messages. We write the specifications, build the working software and publish it all under an open license. For now we also decide which companies may vouch for phone numbers on the network, a job we intend to hand to a neutral body. We build the technology; we do not sell phone plans. The phone service built on our work is Haiven Mobile, a company we own and one operator among the many the network is designed for.

History

Where this came from

3NUM started in 2022 after its founder was SIM-swapped: a stranger walked away with the founder's phone number after one call to a carrier, and every account that reset by text message went with it. The company set out to make a phone number something no carrier employee could hand to anyone.

The first answer put numbers on Ethereum: a number you held with your own keys, encrypted messaging between those numbers, and a bridge to the ordinary phone network. It worked, and it taught us the real constraint. A private network is only useful if it can reach everyone, and people will not adopt a new wallet, a new app and a new number to get there. It had to work with the number and the identity people already have, and no single company, including ours, could sit in the middle. Those first products shipped between 2022 and 2024 and are retired.

So in 2025 we rebuilt the idea as an open standard, ATSMS, on AT Protocol, the open identity network behind Bluesky, where millions of people already hold an identity that is theirs. The idea carried over whole: a number should belong to a person through keys only they hold, and reaching everyone else should not mean giving that up.

One problem remained. Nearly every encrypted messenger, including the ones that run group chats well, relies on a server to keep the group's changes in order, and whoever runs that server is a company in the middle. A network meant to have many independent operators cannot have one. In 2026 we built ATSMS's group encryption on BeeKEM, published research from Ink & Switch that lets every phone in a group agree on the same keys with no server in charge. That is the piece that turns "many operators" from a promise into a property of the protocol. The articles from the first generation are still published here, kept as they were written.

2019A SIM swap
The founder's number is moved to a stranger's phone with one call to a carrier. The problem the company exists to solve.
20223NUM is founded
Phone numbers you hold with your own keys, with encrypted messaging between them. Backed by BlueYard, Notation, Acequia and A100x.
2022 – 2024The first generation
Secure numbers, an encrypted messenger and a bridge to the ordinary phone network. Shipped, learned from, retired.
2025ATSMS
The idea is rebuilt as an open standard on AT Protocol and published with working software.
2026Groups on BeeKEM, calls, the first operator
Group encryption with no server in charge, built on BeeKEM so the network can have many operators; calls from the ordinary phone network; and Haiven Mobile as the first company offering service on the network.

The first generation shipped as 3NUM Shield, MobileKey, ENS Digits and Speak.3Z.

Backed by

Contact

info@3num.co for everything: press, partnerships, operators, security (see security first), data requests.

Bluesky @3num.co · X @3numLabs · GitHub 3numlabs

Press boilerplate

3NUM Labs builds open infrastructure for private phone calls and messages. Its ATSMS protocol brings end-to-end encrypted messaging and calls to the AT Protocol identity people already have (the open identity network behind Bluesky), with phone numbers bound to identities their holders control and gateways to the ordinary phone network. 3NUM Labs is the operating name of 3NUM Inc.