Threema arrives on the desktop. Threema Web allows to conveniently chat from the computer without compromising security. The handling is intuitive, and the user has full access to all chats, contacts, and media files.
Highest security and data restraint
As to be expected, Threema’s way of implementing a web client ensures both highest security and maximum data restraint. Instead of using a server for message synchronization, Threema Web establishes an encrypted direct connection between browser and mobile device. This way, messages can be synchronized without having to pass a server. If browser and mobile device are connected to the same network, the data packets never leave the network. In contrast to common, server-based approaches, Threema Web significantly reduces the digital footprint and limits the generation of metadata to the bare minimum. After a session has ended, the synchronized messages are deleted immediately on the desktop. Threema Web acts as an extension of the Threema app and meets the high security standard set by the Threema app.
Complete message synchronization
The sole requirement to use Threema Web is a current web browser (Chromium, Google Chrome, Mozilla Firefox, or Opera). By scanning a QR code, browser and mobile device are connected at once. All chats are fully available on the desktop, and the devices are synchronized seamlessly. UI-wise, Threema Web is modeled after the Threema app. Messages are sent and received just like on the mobile device; images and files can be conveniently sent using drag and drop.
Threema Web is open source; the source code is available on GitHub, and even self-hosting is possible. To handle the direct communication between browser and mobile device, SaltyRTC is used. SaltyRTC adds an additional encryption layer to the open standard WebRTC and ensures a secure connection between browser and mobile device. Signaling is also carried out by SaltyRTC using strong encryption. The SaltyRTC protocol was developed specifically for Threema Web and is based on the tried and trusted NaCl cryptography library, which is highly regarded by experts.