SimpleX Chat
Version: 5.4.4 Web: https://simplex.chat
There was a time when communicating via centralised servers was the only option for non-technical everyday users. But that’s passé, thanks to messengers such as SimpleX Chat, which connects participants directly to each other, and doesn’t even require identifiers like user IDs.
SimpleX is a cross-platform app that works on all mobile platforms and desktop OSes. On Linux, it’s distributed as an AppImage that you can download from its website. Then give it executable permissions either from the file manager or with chmod +x .
When you first launch the app, you’re asked to create a profile, which involves entering your name and a database passphrase. SimpleX prompts for this passphrase on subsequent launches. Keeping in line with its privacy promise, the profile including the passphrase is stored locally on your computer or device.
SimpleX communicates via the homegrown SimpleX Messaging Protocol (SMP) this virtually negates the possibility of Man In The Middle snooping. The app uses several security mechanisms for securing the connection channels, such as double ratchet and endto-end encryption.
SimpleX has two means of establishing contact: a
SimpleX contact address or a one-time invitation link. The latter, as the name suggests, can only be used once. On the other hand, a SimpleX contact address can be used many times, and is designed for sharing on social media platform profiles or in email signatures.
Both addresses are available as QR codes or a long string of plain text. The channel through which you share the addresses doesn’t have to be secure, as long as you can confirm the identity of the recipient. Also, unlike addresses in other platforms, SimpleX addresses are not used to deliver the messages, only to establish the connection. Once connected, you can exchange text messages, and make audio and video calls, as you would on a regular, centralised chat client.