SEND: Quantum-Safe Messenger
Everyone
info
1+
Downloads
About this app
SEND — encryption for the day today's encryption breaks.
Every message, every call sent through SEND is protected by two independent kinds of math working together: the elliptic-curve cryptography protecting your data today, and a post-quantum algorithm (ML-KEM-768) designed to withstand the computers of tomorrow. Both have to fail before anything you send is ever exposed. That's not a marketing phrase — it's how the keys are actually derived, and you can read exactly how in our published Security Posture document.
SEND is Secure Encrypted Network for Direct messaging: a post-quantum, end-to-end encrypted messenger built for people who want more than a promise.
WHAT MAKES SEND DIFFERENT
• Hybrid post-quantum encryption (X25519 + ML-KEM-768) on every conversation, re-keyed automatically as you talk — not just at the start.
• A full Double Ratchet, the same forward-secrecy and post-compromise-security construction serious encrypted messaging is built on.
• Sealed-sender messages: our relay never learns who sent what. Every destination is a one-way hash, not an address book.
• Encrypted calls with an optional relay that hides your IP address from whoever you're calling — on by default.
• Constant-bitrate audio: even the pattern and timing of your call's data resists giving away when you're speaking.
• Group messaging with membership limits enforced by the server — without the server ever learning who your group's members actually are.
• A duress PIN that wipes your data silently if you're ever forced to unlock your phone.
• Disguise mode: hide SEND behind a calculator, weather, or notes app icon.
• Zero server-side storage. No database, no message logs, no analytics — by architecture, not by policy.
RADICAL HONESTY, NOT MARKETING
We publish a public Security Posture document that states, line by line, exactly what's been verified in the code — and just as plainly, what SEND does NOT do yet. No independent audit has happened. We say so, first, before anything else. Every other claim in this listing is something you can go check yourself.
FOR TEAMS AND ORGANIZATIONS
Sovereign and Enterprise plans let a business run its own SEND infrastructure end to end, or provision dedicated relays and manage every linked account and device from one dashboard.
Available on Android and iOS. Also distributed as a direct APK for anyone who'd rather not go through an app store at all.
SEND. Built for what comes after "encrypted" stops being enough.
Every message, every call sent through SEND is protected by two independent kinds of math working together: the elliptic-curve cryptography protecting your data today, and a post-quantum algorithm (ML-KEM-768) designed to withstand the computers of tomorrow. Both have to fail before anything you send is ever exposed. That's not a marketing phrase — it's how the keys are actually derived, and you can read exactly how in our published Security Posture document.
SEND is Secure Encrypted Network for Direct messaging: a post-quantum, end-to-end encrypted messenger built for people who want more than a promise.
WHAT MAKES SEND DIFFERENT
• Hybrid post-quantum encryption (X25519 + ML-KEM-768) on every conversation, re-keyed automatically as you talk — not just at the start.
• A full Double Ratchet, the same forward-secrecy and post-compromise-security construction serious encrypted messaging is built on.
• Sealed-sender messages: our relay never learns who sent what. Every destination is a one-way hash, not an address book.
• Encrypted calls with an optional relay that hides your IP address from whoever you're calling — on by default.
• Constant-bitrate audio: even the pattern and timing of your call's data resists giving away when you're speaking.
• Group messaging with membership limits enforced by the server — without the server ever learning who your group's members actually are.
• A duress PIN that wipes your data silently if you're ever forced to unlock your phone.
• Disguise mode: hide SEND behind a calculator, weather, or notes app icon.
• Zero server-side storage. No database, no message logs, no analytics — by architecture, not by policy.
RADICAL HONESTY, NOT MARKETING
We publish a public Security Posture document that states, line by line, exactly what's been verified in the code — and just as plainly, what SEND does NOT do yet. No independent audit has happened. We say so, first, before anything else. Every other claim in this listing is something you can go check yourself.
FOR TEAMS AND ORGANIZATIONS
Sovereign and Enterprise plans let a business run its own SEND infrastructure end to end, or provision dedicated relays and manage every linked account and device from one dashboard.
Available on Android and iOS. Also distributed as a direct APK for anyone who'd rather not go through an app store at all.
SEND. Built for what comes after "encrypted" stops being enough.
Post-quantum encrypted messaging & calls. Private by design, not by promise.
Updated on
Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
- No data shared with third partiesLearn more about how developers declare sharing
- This app may collect these data typesDevice or other IDs
- Data is encrypted in transit
- You can request that data be deleted
What’s new
Reliability fixes and a faster start.
• The app no longer sits on the logo before asking for your PIN. There was a deliberate two-second pause serving no purpose, paid on every open.
• After the screen locks, the PIN is always asked for on return. Pulling down Control Centre still isn't.
• On iPhone, crash reports are being sent again — they never worked before.
• The app no longer sits on the logo before asking for your PIN. There was a deliberate two-second pause serving no purpose, paid on every open.
• After the screen locks, the PIN is always asked for on return. Pulling down Control Centre still isn't.
• On iPhone, crash reports are being sent again — they never worked before.
App support
phone
Phone number
+351938026400
About the developer
Sérgio Filipe Calado Cabral Ribeiro
sergio.filipe.calado@gmail.com
R. João de Deus 29 1º F
8135-159 Almancil
Portugal
