Bitchat is Jack Dorsey's internet-free messaging app

Jack Dorsey, known as the co-founder of Twitter, has put the public domain source code for a new software called Bitchat online. It enables digital chats via Bluetooth, without any internet connection or central server, initially for iOS and MacOS. Bitchat focuses on data protection and reliability.

Users do not have to register or identify themselves anywhere; there are no central servers or other instances that harvest metadata and through which the project could be corrupted or shut down. Transmissions are compressed and end-to-end encrypted. In addition, dummy messages and random delays are intended to make it more difficult to assign specific messages or usernames to individual users based on their usage behavior.

Transmission will initially take place exclusively via Bluetooth Low Energy. Its range is limited to a few dozen meters, which is why Bitchat wants to set up mesh networks. Participants within range accept the encrypted messages and forward them to other participants until the message reaches the addressed recipient. Up to seven transmissions are planned. Devices that are contacted particularly frequently theoretically store messages for an unlimited period of time; on other devices, they are deleted if they could not be delivered after twelve hours.

Similar to Briar

There is no obvious commercial business model, which means that no spam filters for the encrypted messages are foreseeable. Whether Bitchat will succeed depends on the participants alone. One white paper is already considering adding transmissions via direct WLAN connections and LoRa to Bluetooth Low Energy.

The name may be an unfortunate choice, as it can be pronounced as "bitch at". Dorsey's name is certainly attracting attention, even if the basic concept is not new. The Briar app has been available for Android for years, which sends encrypted messages between participants via Bluetooth, direct Wi-Fi connections or the internet-based Tor network. In an emergency, Briar can even send messages as files on data carriers.

The Meshtastic project (including its French offshoot Gaulix) exists for LoRa, but requires LoRAWAN gateways in addition to standard smartphones. The idea pursued by Briar and Bitchat is also the basis for the Berty project, which was founded in 2018 and aims to use the specially developed "Wesh Network" with the IPFS (InterPlanetary File System) transmission protocol. However, Berty has become very quiet.

LoRa and LoRaWAN

LoRa is used to transport small data packets (up to 256 bytes) over long distances using little energy. The technical radio trick: LoRa as a physical layer consists of a narrowband carrier that is moved up or down in a comparatively wide channel. These transmissions, known as "chirps", are easily recognizable in the general noise and are therefore very robust against interference.

The method is optimized for payloads of a few bytes and is used, for example, in Amazon Sidewalk. LoRa is the physical transmission technology for the LoRaWAN network protocol, which is responsible for the network structure, addressing, encryption and channel specifications.

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