800 Points
You should definitely use open-source, encrypted messengers such as Briar, Signal, Threema or SimpleX. Avoid insecure commercial messengers such as WhatsApp, Telegram and Co.

More information

If you are unsure which messengers are good or if you need arguments to convince family and friends, you should definitely take a look at Kuketz's messenger matrix. There you can easily compare the individual messengers according to functions and security aspects. Also bear in mind that the police in some countries have already launched their own chat apps to make it easier to obtain investigation data.

Sources and further links

  1. SPQR encryption from Signal is said to be unbreakable for quantum computers, tarnkappe.info, (de), 2025-10-04
  2. Courts may use FBI cryptochats, spiegel.de, (de), 2025-01-08
  3. Telegram delivers data to investigators, tagesschau.de, (de), 2024-10-07
  4. Telegram: Not suitable for confidential chats, nd-aktuell.de, (de), 2024-10-06
  5. WhatsApp? No, thank you., netzpolitik.org, (de), 2024-09-30
  6. Telegram’s peer-to-peer SMS login service is a privacy nightmare, techcrunch.com, (en), 2024-03-25
  7. Signal will soon allow you to hide your phone number, netzpolitik.org, (de), 2024-02-20
  8. Whatsapp lets other users access device information, golem.de, (de), 2024-01-17
  9. madaidans Telegram review, madaidans-insecurities.github.io, (en), 2022-03-05
  10. bkil secuchart - Comparison of messengers, bkil.gitlab.io, (de)
  11. Messenger matrix, messenger-matrix.de, (de)
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