SecureBit Desktop

Native desktop applications for SecureBit Chat — a zero-server, peer-to-peer messenger with end-to-end encryption.

Downloads · Installing · Automatic updates · Verifying your download · Security · Privacy

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Downloads

Current release: 0.3.0

Platform	Requirements	File
Windows	Windows 10 (1809+) or 11, x64	SecureBit.Chat_0.3.0_x64-setup.exe
macOS	macOS 11+, Intel or Apple Silicon	SecureBit.Chat_0.3.0_x64.dmg
Linux	glibc 2.31+ (Ubuntu 20.04+, Debian 11+, Fedora 35+)	SecureBit.Chat_0.3.0_amd64.AppImage

The macOS build is compiled for Intel and runs on Apple Silicon through Rosetta.

All releases are on the releases page.

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Installing

Windows

1. Run SecureBit.Chat_0.3.0_x64-setup.exe.
2. SmartScreen may warn about an unrecognised app — choose More info → Run anyway.
3. Follow the installer. It lands in C:\Program Files\SecureBit Chat\.
4. Allow network access if Windows Firewall asks; the app needs it to reach peers directly.

macOS

1. Open the .dmg and drag SecureBit Chat into Applications.
2. On first launch, right-click the app and choose Open — a plain double-click will be blocked by Gatekeeper.
3. Grant microphone and camera access when prompted, if you intend to use calls.

If the app still refuses to start:

xattr -d com.apple.quarantine "/Applications/SecureBit Chat.app"

Linux

wget https://github.com/SecureBitChat/securebit-desktop/releases/download/v0.3.0/SecureBit.Chat_0.3.0_amd64.AppImage
chmod +x SecureBit.Chat_0.3.0_amd64.AppImage
./SecureBit.Chat_0.3.0_amd64.AppImage

To add it to your application menu:

sudo mv SecureBit.Chat_0.3.0_amd64.AppImage /opt/securebit-chat.AppImage

cat > ~/.local/share/applications/securebit-chat.desktop <<'EOF'
[Desktop Entry]
Name=SecureBit Chat
Exec=/opt/securebit-chat.AppImage
Type=Application
Categories=Network;InstantMessaging;
EOF

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Automatic updates

The app checks for a new version shortly after launch, and on demand when you click the version number next to the SecureBit wordmark in the sidebar. When one is available you get a prompt: Update now downloads and installs it, then offers to restart.

Why the update is trustworthy. Every update bundle is signed with a key that never leaves the maintainer's machine, and the app verifies that signature against a public key compiled into the binary before installing anything. A bundle that is unsigned, altered, or signed by any other key is refused. Neither GitHub nor the network is part of the trust model — compromising either does not let anyone push code into your installation.

Availability

Platform	Status
macOS	Automatic updates from 0.3.0 onward
Windows	Manual for now; automatic from the next build
Linux	Manual for now; automatic from the next build

Version 0.1.0 predates the updater on every platform, so upgrading from it is a one-time manual download.

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Verifying your download

Compare the checksum of the file you downloaded against the list below.

# macOS / Linux
shasum -a 256 <file>

# Windows
Get-FileHash .\SecureBit.Chat_0.3.0_x64-setup.exe -Algorithm SHA256

File	SHA-256
SecureBit.Chat_0.3.0_x64-setup.exe	1483902008b5b1e1192b01af73d045f4bc3c2c5cb645c273c1cb63f048f74f62
SecureBit.Chat_0.3.0_x64.dmg	81e4e516692635aa13e927cd37420d3c1bd8a8d6aaec065b3291b8a63147cf59
SecureBit.Chat_0.3.0_amd64.AppImage	f3d6cc19d16b97a61b2cce16695084129f22f6842af8433a6fc7b007fe8316d0

The macOS build is additionally code-signed; you can inspect it with:

codesign -dvv "/Applications/SecureBit Chat.app"

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Security and trust

The split

Everything that touches your messages, keys or connections is open source. The desktop applications are a wrapper around it.

┌──────────────────────────────────────┐
│  Desktop application (proprietary)   │
│  Native UI, platform integration,    │
│  window and notification handling,   │
│  update delivery                     │
└───────────────┬──────────────────────┘
                │ calls into
┌───────────────▼──────────────────────┐
│  securebit-core (open source)        │
│  Key exchange, encryption, protocol, │
│  verification, file transfer crypto  │
└──────────────────────────────────────┘

What you can audit

Repository	Contents	License
securebit-core	Every cryptographic operation and the full protocol implementation	Apache-2.0
securebit-chat	The complete web client, including its UI	MIT

Start with SECURITY_MODEL.md and THREAT_MODEL.md in the core repository — they state what is guaranteed and, just as importantly, what is not.

git clone https://github.com/SecureBitChat/securebit-core.git
cd securebit-core
cargo test

The test suite pins the protocol against the web implementation, so both clients cannot silently drift apart.

How a session is secured

• Ephemeral ECDH P-384 key exchange, signed with ECDSA P-384, giving forward secrecy
• AES-256-GCM for messages and file chunks, with HMAC-SHA-256 over the payload
• A short verification code that both peers derive independently — comparing it out of band is what rules out an attacker in the middle
• No server sees your traffic: connections are peer-to-peer, and a relay is used only when a direct connection is impossible, where it forwards ciphertext it cannot read

Reporting a vulnerability

Email security@securebit.chat rather than opening a public issue. Include a description, the affected version, and a reproduction if you have one. Responsible disclosure, 90-day window.

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Privacy

The applications collect nothing. There is no analytics, no telemetry, no usage statistics, and no crash reporting.

There is also nothing to collect on a server, because there is no server holding your data: no accounts, no stored messages, no contact lists, no connection logs, no keys.

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System requirements

Platform	Minimum	Recommended
Windows	Windows 10 (1809+), 4 GB RAM, 200 MB disk	Windows 11, 8 GB RAM
macOS	macOS 11, 4 GB RAM, 200 MB disk	macOS 13+, 8 GB RAM
Linux	glibc 2.31+, 4 GB RAM, 200 MB disk	Ubuntu 22.04+ / Fedora 38+, 8 GB RAM

Calls need a webcam and microphone. Bandwidth: roughly 128 kbps for audio, 1 Mbps for video.

Networking: the app uses WebRTC and needs outbound UDP for STUN (port 3478) and peer traffic. Restrictive firewalls fall back to a TLS relay on port 443.

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Status and roadmap

The desktop applications are in public beta. The cryptographic core is production-ready and shared with the web client; what is still being refined is platform integration and UI polish.

Planned:

• Automatic updates on Windows and Linux
• Distribution through the Microsoft Store, Mac App Store and Snap Store
• Mobile applications
• Group chats
• Post-quantum key exchange

Feature requests are tracked in Issues.

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Support and contributing

Questions and bug reports: Issues or support@securebit.chat.

The desktop wrapper is not open source, but the parts that matter are, and contributions there are welcome — securebit-core for cryptography and protocol, securebit-chat for the client itself.

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License

The desktop applications are proprietary and free for personal and commercial use. Redistribution requires permission; reverse engineering is not permitted. See LICENSE.

The open-source components keep their own licenses: securebit-core under Apache-2.0, securebit-chat under MIT.

Copyright © 2025-2026 SecureBit. All rights reserved.