QGap encrypts every message with a one-time pad – the only encryption method that is mathematically proven to be unbreakable. Use it fully offline: transfer messages via animated QR codes, no internet involved.
📱 Download for Android 🖥️ Download for WindowsEvery byte of your message is encrypted with a byte from a random key file that is never reused. Without the key file, the ciphertext is provably worthless – to any attacker, any supercomputer, any AI.
Key exchange happens hand-to-hand via USB stick. Messages can be transferred as animated QR codes from screen to camera – your device never needs to go online. No cloud, no servers, no traces.
A one-time-pad ciphertext contains no exploitable patterns whatsoever. No language model and no analysis software can reconstruct or store content from the transmitted data.
Optionally, chats can be synced through a cloud transport – messages remain end-to-end OTP-encrypted. The server only ever sees random bytes.
No in-person key exchange possible, or too much effort? Then QGap offers a proven hybrid scheme as an alternative: content is encrypted with AES-256-GCM, and the random AES key with the recipient's RSA-2048 key. Chat securely right away – without handing over a one-time-pad key file first.
The source code of QGap – including all of the encryption – is publicly available under the GNU AGPL v3. Anyone can independently audit the encryption – trust through transparency, not promises. The code remains protected by copyright; use is governed by the license.
Full functionality on Android phones and Windows PCs. Messages, files, voice messages, invitations – the same experience everywhere.
Create presentations with song lyrics and images and show them on any screen with a browser – perfect on the go when no projector is available. Share control via QR code with multiple admins: everyone can advance slides, pick songs and display images right from their own phone.
QGap is for everyone who wants to communicate freely – without anyone, any AI or any corporation being able to read along:
The decisive advantage: encryption and decryption can run on a device that is never connected to the internet – the message only crosses the gap (air gap) as a QR code. This defeats spyware, trojans, keyloggers and screen-capture malware alike: on the online device, the plaintext simply does not exist – all that can be seen there is unreadable ciphertext.
📱 Android: coming soon on Google Play
🖥️ Windows: QGap.exe – download link coming soon
🔍 Source code: GitHub link coming soon
E-mail: paulprog@abwesend.de