Privacy is not optional
OSHI is a free, open-source Swiss-developed messenger for iOS that works without internet connection via mesh networking. Send encrypted messages peer-to-peer, bypass internet censorship with 6 steganographic covert channels, and communicate privately with no phone number required. Powered by on-device AI, Tor, and an encrypted relay we run ourselves — enabling censorship-resistant communication through peer-to-peer mesh messaging.
Offline maps, AI assistant, image viewer, and Android APK — OSHI keeps growing while staying private.
Download entire regions for fully offline navigation. Search streets, find POIs (restaurants, pharmacies, gas stations, hospitals), and plan itineraries — all without internet.
NEWOffline directions for walking, driving, and cycling. Like Organic Maps, built right into your secure messenger — no third-party tracking.
NEWPowered by Apple Intelligence (iOS 26+). Ask questions, get summaries, draft messages — entirely on-device. Your data never leaves your phone.
iOS 26+Find restaurants, pharmacies, gas stations, hospitals, and more — directly on the offline map. No internet, no tracking, instant results.
NEWTap any image in group chats to view fullscreen with pinch-to-zoom. Swipe to browse all shared photos in the conversation.
NEWOSHI is now available as a direct APK download for Android. No Play Store required — sideload and start messaging privately.
ANDROID12 privacy features including offline maps, on-device AI, covert steganography, and mesh networking — all designed with your security as the top priority
AES-256-GCM authenticated encryption with the Double Ratchet protocol. Only you and your recipient can read messages.
Connect directly with nearby devices via Bluetooth and WiFi. No internet required for local communication.
Crystal-clear voice calls with real-time encryption. Add voice effects for extra privacy and fun.
There is no account and no phone number, and mesh messages never reach a server. When a message does go through our relay, it sees the sender and recipient public keys, the time and the size — never the contents.
Set messages to auto-delete after reading. Leave no trace of sensitive conversations.
Messages go peer-to-peer over Bluetooth and WiFi with no server involved at all. Only when no peer is reachable do they fall back to our own encrypted relay, optionally over Tor.
Smart corrections, translations, tone reformulation, and AI assistant — all 100% offline using Apple Foundation Models.
Create Telegram-like bots with Python. Automate messages in channels and groups with a simple API.
6 advanced steganographic covert channels. Hide messages in web traffic, images, DNS queries, and text. Bypass censorship in restrictive networks.
Download regions for offline use. Turn-by-turn navigation for walking, driving, cycling. Search streets and POIs — no internet needed.
View images fullscreen with pinch-to-zoom in group chats. Swipe to browse all shared photos in the conversation.
Direct APK download available. No Play Store required — sideload OSHI on any Android device for private messaging.
Powerful language AI that runs 100% on your device. No data ever leaves your phone.
AI-powered spelling and grammar correction in any language. Context-aware, not just dictionary lookup.
Rewrite your message in 6 tones: Formal, Casual, Friendly, Professional, Playful, Persuasive.
Translate messages to 16+ languages. Translate received messages with one tap.
Ask questions directly in the chat. Get instant answers without leaving the conversation.
Messages automatically route through the best available path
Direct device-to-device. No server is involved at all.
When no peer is in range, we carry the message on our own server
Hides your IP address from the relay
When networks are restricted, OSHI finds a way. 6 independent covert channels disguise your messages as normal web traffic.
Data encoded as Google Analytics cookies, ETags, and tracking headers. Indistinguishable from normal browsing.
Payload hidden in DNS subdomain queries. Works even when HTTP traffic is heavily monitored.
TLS shows allowed CDN domain, but HTTP routes to relay. Network sees cloudfront.net — we reach our server.
5 strategies: Google search, analytics beacons, form submissions, API calls, and image requests. DPI sees normal browsing.
Advanced image embedding that hides encrypted data in photo textures. It looks like an ordinary photo to the eye, but steganalysis tools can detect LSB embedding, so the payload is always encrypted first.
Zero-width Unicode, homoglyph substitution, and whitespace encoding. Messages hidden inside normal-looking text.
Built in Switzerland under strict Swiss privacy law, OSHI uses the same encryption protocols trusted by security experts worldwide. Your data is protected at every step.
On iOS 26 and macOS 26, and only when both people in a conversation are running a version that supports it, OSHI negotiates X-Wing — ML-KEM-768 combined with X25519 — for the key exchange. The app ships with a deployment target of iOS 17.5, so older devices keep the classical X25519 exchange; the upgrade is negotiated per conversation and happens silently once both ends can.
The reason to care is harvest-now-decrypt-later: an adversary who can record traffic today can simply store it and wait for a quantum computer capable of breaking X25519. Anything captured now would then become readable retroactively. A key exchange that already resists quantum attack is the only thing that protects a conversation you are having today against a machine that does not exist yet.
It is deliberately hybrid and never post-quantum alone. The shared secret depends on both the ML-KEM-768 and the X25519 halves, so a future break of ML-KEM cannot make a session weaker than it would have been with X25519 on its own. If the hybrid exchange cannot be completed, it fails closed rather than quietly falling back to something weaker.
Implementation: OSHI/PostQuantumKEM.swift, using CryptoKit's XWingMLKEM768X25519 under a .hybridWhenAvailable policy. Open source and auditable like the rest of the app.
OSHI's covert communication features are designed to protect freedom of expression and personal safety in regions where basic human rights are at risk. These tools are intended for journalists, human rights activists, political dissidents, and civilians in conflict zones.
The use of covert channels is subject to the laws of your jurisdiction. Users are solely responsible for ensuring compliance with local regulations.
Learn more about what makes OSHI the most complete private messenger
Send encrypted messages without internet via Bluetooth and WiFi Direct. Works offline, no cell service needed.
Read full guide →6 advanced channels that hide your messages in normal traffic. Bypass censorship and deep packet inspection.
Read full guide →Translation, smart replies, and AI assistant powered by Apple Foundation Models. 100% offline, zero cloud data.
Read full guide →Join thousands of users who trust OSHI for their private communications.