Open Source / Apache 2.0

MeshCipher

Private messaging that works everywhere. Even off the grid. Five independent transport layers. One unbreakable encryption standard.

Protocol Signal (X3DH + Double Ratchet) Encryption AES-256-GCM Platform Android

Built for privacy.
Designed for resilience.

Every layer of MeshCipher is engineered to protect your communications, whether you have internet access or not.

End-to-End Encryption

Signal Protocol with X3DH key agreement and Double Ratchet for perfect forward secrecy on every message.

SIGNAL PROTOCOL

Five Transport Modes

Direct relay, Tor relay, WiFi Direct, Bluetooth mesh, and P2P Tor hidden services. Works with or without internet.

MULTI-TRANSPORT

Hardware-Bound Identity

ECDSA P-256 keys generated and stored in Android Keystore TEE/StrongBox. Keys never leave secure hardware.

ANDROID KEYSTORE

Encrypted Database

All local data encrypted at rest with SQLCipher AES-256. Database key derived from hardware-backed Android Keystore.

SQLCIPHER AES-256

Disappearing Messages

Configurable auto-delete with multiple retention periods. Messages and media cleaned from both database and filesystem.

AUTO-DELETE

Metadata Protection

Tor modes hide IP addresses. Offline modes leave no network trace. The relay server sees only sender/recipient IDs and encrypted blobs, never plaintext or contacts.

TRAFFIC ANALYSIS RESISTANCE

Secure Media

Images, video, and voice messages encrypted with per-message AES-256-GCM keys before transport.

AES-256-GCM

Open Source

Fully auditable codebase under Apache 2.0 license. Every line of code is public and verifiable.

APACHE 2.0

Five ways to deliver.
One encryption standard.

Choose your transport based on your threat model. All modes deliver the same Signal Protocol-encrypted payload.

The encryption layer is completely independent of the transport layer. Switching modes changes how messages travel, not how they're protected.
Direct
Fast delivery through HTTPS relay server. The relay is zero-knowledge: it only forwards encrypted blobs and never sees plaintext. The relay server is open source and self-hostable.
Network HTTPS
Range Global
Speed Fast
Privacy IP visible
Server Required
Tor Relay
Messages routed through Tor network, hiding your IP address from the relay server. The zero-knowledge relay sees only encrypted blobs, never content.
Network HTTPS + Tor
Range Global
Speed Medium
Privacy IP hidden
Server + Orbot
WiFi Direct
Peer-to-peer over WiFi P2P. No internet, no servers, no network trace left behind.
Network WiFi P2P
Range ~100m
Speed Fast
Privacy No trace
Server None
BLE Mesh
Multi-hop Bluetooth mesh routing. Messages bounce between nearby devices to reach their destination.
Network BLE
Range 30-100m/hop
Speed Low
Privacy No trace
Server None
P2P Tor
Direct connection via Tor hidden services. Your device is its own anonymous .onion endpoint.
Network Hidden svc
Range Global
Speed Medium
Privacy Anonymous
Server None

Transparent by design.
Auditable by anyone.

MeshCipher's security claims are backed by open source code and public documentation. We invite scrutiny.

Relay Server: Zero-Knowledge

The relay server only stores encrypted blobs and sender/recipient device IDs. It cannot read message content, see your contact list, or correlate conversations. The server code is open source and self-hostable.

View relay server source ->

Metadata Exposure by Mode

Direct mode: relay sees sender/recipient IDs and IP. Tor Relay: relay sees IDs only, IP hidden by Tor. WiFi Direct / BLE Mesh: no server, no network log. P2P Tor: no server, both parties anonymous via .onion addresses.

Read networking docs ->

Cryptographic Documentation

Full documentation of all cryptographic primitives, key generation, storage, and protocol flows. ECDSA P-256 identity keys, X3DH key agreement, Double Ratchet, AES-256-GCM, SQLCipher.

Read crypto docs ->

MeshCipher has not yet undergone a formal third-party security audit. If you are a security researcher, we welcome and encourage independent review of the codebase and protocol implementation.

Report a Vulnerability

Three steps to secure communication.

No phone number. No email. No accounts. Just cryptographic identity.

1

Create Identity

A hardware-bound ECDSA key pair is generated inside your device's secure enclave. Your identity never leaves the chip.

2

Add Contacts

Exchange keys via QR code scan when in person, or share your public key over any trusted channel for remote contacts. In-person verification is strongest, but not required.

3

Message Securely

Choose your transport mode and send. Signal Protocol encrypts everything end-to-end regardless of how it travels.

Built because privacy
shouldn't be optional.

MeshCipher exists because private communication shouldn't depend on a single company's infrastructure or require an internet connection.

Every transport mode, every encryption layer, every line of code is open source and auditable.

Core Maintainer

Nick Evans

First year MSci Student, Royal Holloway