An encrypted messenger with money in the thread
SIGNET is an end-to-end encrypted messenger for iPhone with a self-custodial bitcoin, Lightning and USDt wallet built into the chat. There is no phone number and no account: your identity is a 12-word recovery phrase generated on your device, and the delivery server only ever handles sealed, padded envelopes it cannot read. You can run that server yourself.
What every observer can, and cannot, learn
Privacy that is architecture, not a policy. Messages, photos, and voice notes are sealed on your device using MLS, the IETF standard for end-to-end encryption. Here is exactly what our server can read.
The server cannot see
- Your messages, photos, or voice notes
- Who your contacts are, or their names
- The amounts you send or receive
- Your social graph or group membership
- Who pays for SIGNET Pro
The little it does route
- Padded, uniform-size sealed envelopes
- Random routing handles that auto-expire
- A content-free wake for notifications
- A public @handle if you claim one, and its signed rebinding history
The full list, observer by observer, is in the metadata honesty table, published verbatim from the build spec. The SIGNET privacy policy says the same thing in plain legal terms.
Built for real conversations, sealed by default
Messages that live on your phone, not ours
Text, groups, reactions, read receipts and search, sealed before any of it leaves the device.
Bitcoin and USDt
Self-custodial, from the same phrase.
Photos & video
Encrypted media, inline previews.
Voice notes
Record locally, send sealed.
Disappearing messages
They take their media with them.
Groups with forward secrecy
MLS group encryption. Add and remove people without a central operator learning who is in the room, and a removed member reads nothing after they leave.
Notifications decrypted on your phone
The push that wakes the app carries no content and no sender. The preview is decrypted and drawn locally, and you can turn previews off.
Verified contacts
Compare safety numbers in person. If a verified contact's key ever changes, they are un-verified on the spot and sends to them stop until you look.
Backups you control
On by default, sealed under your recovery phrase before they leave the app; switch them off in Settings.
Send bitcoin and USDt the way you send a message
A self-custodial wallet lives beside your chats, created from the same 12-word phrase. No KYC, no custodian. Pay the people you talk to as easily as texting them, or pay a Lightning invoice, a BOLT12 offer or a Liquid address outside SIGNET.
- Your keys, your coins. They never leave the device.
- Dollars, without a rate. USDt is a dollar asset, so $50 is $50 with nothing to convert.
- Pay by handle. Send to tx@hisignet.com, no invoice dance.
- Ask, and split. Request an amount in the thread, or split a bill across a group and watch the shares land.
- Shown in your currency. The server never touches an amount.
Bitcoin over Lightning
Lightning payments usually settle in seconds through the Breez SDK, self-custodial and with no payment code on our server at all. A fee warning stops you before a network fee crosses two percent of what you are sending.
USDt on Liquid
Tether USD rides the Liquid network in the same wallet. Every receive uses a fresh address, and a send settles on chain in about a minute rather than in Lightning's seconds. USDt is issued by Tether, so holding it is a claim on Tether rather than on bitcoin.
Know you reached the right person
Most encrypted messengers ask you to trust the directory that hands out your contact's key. SIGNET makes that directory prove itself.
A signed, auditable log
Every @handle has an append-only log. Each entry is signed by the identity key it binds and chained to the entry before it, and the server signs the head of that chain over a number your phone picks. Your phone remembers what it saw. For a handle your phone has looked up before, a server that quietly swapped your contact's key would have to keep a private fork running forever, and the moment it slips it leaves a signed contradiction on your device. Handle owners audit their own log every time they open the app, and signed heads ride between contacts inside ordinary messages, so a fork has to survive those too.
A fingerprint in the handle
Share yourself as @tx#k7m2-9qxa-3fdd-8hh1. Those characters are a fingerprint of your identity key, so a handle someone got from you refuses to resolve to anybody else. First contact then trusts the channel the handle came over instead of the directory.
Safety numbers, compared in person, are still the strongest check, and every new thread says plainly that it is unverified until you make it.
Records that do not survive a seized device
Encryption in transit is the easy half. The harder question is what a phone in someone else's hands gives up.
App lock that actually locks
Face ID when you open SIGNET and, by default, every time it goes to the background. Locking closes the encrypted database and drops its key rather than drawing a screen over it, and the wallet disconnects with it.
Erase this device
One action destroys the keys first, then the messages, media, payment history and delivered notifications. What was on the phone is not recoverable from the phone. Your funds and identity come back from your phrase.
Secure delete
Deleted rows are overwritten instead of being left behind as free pages, and the database is compacted after every expiry sweep. Expiring a message takes its media with it.
Out of your backups
The live database is excluded from iPhone and iCloud backups, so no copy of it rides along. Encrypted SIGNET backups to your own iCloud are on by default, sealed under your recovery phrase before they leave the app, and yours to switch off.
What software cannot do, said plainly: it cannot stop someone who holds your unlocked phone or knows your passcode, and it cannot reach copies that already sit on other people's phones or on a public chain, and an encrypted SIGNET backup already in your iCloud stays there, unreadable without your phrase, until you delete it.
Group encryption that can be ready for a quantum computer
Every SIGNET device on the current build publishes key material on the hybrid post-quantum suite ML-KEM-768 with X25519, alongside the classical one. A group created on the hybrid suite is post-quantum on the first join and on every rekey after it, because MLS runs the key exchange again on each one.
What is available today
The hybrid suite is live on the wire and any contact on the current build can be added to a group that uses it. New groups still default to the classical suite until the install base has updated, because a phone on an older build cannot join a post-quantum group.
What is still classical
Signatures are Ed25519, the same position Signal and iMessage are in today. The server's challenge authentication, the TLS pinning, the backup key and Lightning itself are classical too. We would rather say so than round it up.
A bigger daily limit, and nothing a server needs to know
SIGNET is free, and the free tier is a whole messenger with a working wallet. Pro exists for people who move more money than a safety cap should allow by default.
Free
$0
Sends up to about $100 a day, which is also the ceiling on any single payment. Receiving, holding and requesting have no limit at all. Spending insights cover the last 7 days.
Pro
US$3.99 / month · US$39.99 / year
Sending rises to the app's money-safety ceiling, about $50,000 a day. Adds 90 days of spending insights per asset and CSV statements, both computed on the device.
Apple verifies the subscription on your phone. SIGNET runs no account server, the delivery server carries no entitlement, and the receipt never leaves the device, so nobody here learns who subscribed. Security and privacy are never behind the price: the lock, the erase, notification previews, key transparency, USDt and backups are all free.
No sign-up, because there is nothing to sign up for
Create an identity
Tap once. A 12-word recovery phrase is generated on your device. That is your whole account.
Message and pay
Invite a contact, start talking, send bitcoin or USDt in the same thread. All of it end-to-end encrypted.
Own your keys
The same phrase restores your identity, contacts, and wallet on any new phone. Nothing to leak.
Do not trust us. Run the server yourself.
SIGNET works with any self-hosted delivery server, set up in under thirty minutes with one page of instructions. Your family, your infrastructure. The server is content-blind either way.
$ docker compose up -d signet-dsStandards, not invented crypto
Nothing proprietary. Everything here is a public, reviewed standard, doing exactly what it should.
Questions people ask
What is SIGNET?
SIGNET is an end-to-end encrypted messenger for iPhone with a self-custodial bitcoin, Lightning and USDt wallet built into the chat. Your identity is a 12-word recovery phrase generated on your device, and the delivery server only ever handles sealed, padded envelopes it cannot read.
Does SIGNET need a phone number or an account?
No. There is nothing to sign up for. Tapping once generates a 12-word recovery phrase on the device, and that phrase is the whole account. SIGNET never receives a name, phone number or email address.
Can I send bitcoin inside a chat?
Yes. The wallet sits beside your threads and is derived from the same recovery phrase, so you can send bitcoin over Lightning in the conversation, request an amount, or split a bill across a group. You can also pay a Lightning invoice or offer outside SIGNET.
Can I send USDT in SIGNET?
Yes. SIGNET carries Tether USD on the Liquid network beside bitcoin, in the same self-custodial wallet. You can send USDt in a chat or to a Liquid address, and because a dollar asset is already denominated in dollars there is no exchange rate involved.
Who holds my bitcoin and USDt?
You do. The wallet is self-custodial: its keys come from your recovery phrase and never leave the device. SIGNET cannot hold, move or freeze your funds, and there is no KYC step.
What does the SIGNET server see?
Sealed envelopes padded to uniform sizes, random routing handles that expire, and the timing of delivery. It cannot read messages, media, names, group membership or payment amounts, and, unless you claim a public @handle, it holds nothing that links a routing handle to a person. The metadata honesty table lists every observer line by line.
How do I know I am messaging the right person?
Every @handle lives in an append-only directory log whose entries are signed by the identity key they bind, with the server signing the head of the chain over a number your phone picks. A shareable handle also carries a fingerprint of the identity key, so a handle pasted from your contact refuses to resolve to anyone else. Comparing safety numbers in person remains the strongest check.
Is SIGNET post-quantum?
Partly, and the parts are worth stating plainly. Every device on the current build publishes key material on the hybrid suite ML-KEM-768 with X25519 as well as the classical suite, so a group can be created post-quantum today and every join and rekey after it is hybrid. New groups still default to the classical suite until the install base has updated, and signatures, transport and the backup key remain classical.
What happens if my phone is stolen?
App lock with Face ID closes the encrypted database and drops its key whenever SIGNET goes to the background. Erase this device destroys the keys first and then the messages, media and payment history, so what was on the phone is not recoverable from it. Your funds and identity come back from your recovery phrase on a new device.
Are my notifications readable by Apple?
No. The push that wakes your phone carries no content and no sender, and the preview text is decrypted and rendered on the device. You can turn previews off entirely.
Can I run my own SIGNET server?
Yes. The delivery service is a small Rust server you can deploy yourself and point the app at, typically in under thirty minutes. It is content-blind whether we run it or you do.
What does SIGNET Pro cost and what does it change?
SIGNET Pro is US$3.99 a month or US$39.99 a year through the App Store. It raises sending from the free cap of about $100 a day to the app's money-safety ceiling of about $50,000 a day, and adds 90 days of on-device spending insights per asset plus CSV statements. Apple verifies it on the device, SIGNET runs no account server, and no security or privacy feature is ever behind the price.