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Messengers are popular because they allow fast and direct communication. Disadvantage: a smartphone is mandatory for most messengers, including for desktop use. In addition, they are committed to the software and services of the relevant provider, which all participants must use. This almost inevitably leads to a monopoly, as everyone uses the messenger that most acquaintances and friends also use. However, security vulnerabilities or privacy concerns may persuade some users to switch messengers. All the usual messengers are available to Linux users, some as separate applications or at least in the browser. The article introduces the main services and assesses their security.
Most messengers need to be installed on the smartphone and linked to the phone number. The desktop applications can then be authorized via the app. The messenger element works independently of the smartphone and therefore also without a telephone number. For Threema you first need the paid smartphone app, but the phone number is not used.
End-to-end encryption is standard for almost all messengers. An exception is Telegram, where only the smartphone app supports end-to-end encryption, which you also need to activate with “Secret Conversation”.
In end-to-end encryption, the data is encrypted by the sender’s client and can only be decrypted by the receiver. No unencrypted data is stored on the provider’s servers and can therefore not be read by third parties. However, the procedure can only be considered safe if no backdoors are installed in the clients. Ultimately, this can only be verified if the source code of the software is available. No source code has been published for Whatsapp, the other providers release the source code of the client, the element and the signal as well as that of the server.
whatsapp has a particularly high number of users. Ease of use may have contributed to this, but it may well have been a good time as smartphone adoption grew and the need for a replacement for paid SMS arose. With the smartphone app you can exchange messages, send photos or documents, but you can also make audio and video calls. Linux users can use WhatsApp in the browser (whatsapp web). The displayed QR code must be scanned on the smartphone via the menu item “Paired devices -> Add device”.
Of whatsapp there is also an unofficial standalone program for Linux. It can be installed on Ubuntu 20.04 in the terminal with
|
sudo snap install whatsdesk |
to install. Whatsapp-Web and Whatsdesk only support chat functions, no audio and video telephony.
Telegram can be used for messages to individuals or groups. You can post images, text, and video and audio streams in public groups, which makes Telegram more social network current. Audio and video calls are possible via the smartphone apps; the desktop applications currently only support audio calls and the web browser only supports chat. Desktop applications are available for Windows and Mac OS, Linux users can use a Snap (Ubuntu) or Flatpak (Linux Mint) package.
From signal is the source code client and server software available. Signal is funded by donations, has no commercial interests, nor does it display any advertising in its programs. The functionality of Signal is almost identical to Whatsapp on every platform, both chatting and audio and video calls are possible. Signal is available for Android, iPhone/iPad, Linux, Mac OS and Windows. There is no web interface. The desktop client for Linux can be installed from the signal repository. Copy the necessary command lines to the terminal in Signal’s download area after clicking “Signal for Linux – Debian-based distributions”.
element is open source software and the source code is available at: https://github.com/vector-im available. Funding is through paid software and business services. Element offers chat, audio and video calling on all supported platforms. Login takes place in the client software or in the web interface via an account https://matrix.org. All you need is an email address for this. You can also use Messenger host on your own server. Element can be used in a similar way to WhatsApp: the chats are called “direct messages” here. Groups are organized into private or public “rooms”, which are similar to Telegram.
three months offers the same functions as Whatsapp. The smartphone app costs 3.99 euros, which the Swiss company is financed.
The client software is open source and can be examined by security experts. Threema advertises the exclusive use of its own servers and AVG compliant operation.
The software is available for all common platforms, desktop clients for Linux come as DEB and RPM packages, and a web client is also available. Desktop clients are authenticated via the smartphone. Since a separate Threema ID is used instead of the phone number, the use of messenger remains anonymous.