📱 Voice Calls over E2EE Apps
As explained in 📱 Avoid Calling over Mobile or Landlines, Phone calls are insecure and can be listened in on. We should therefore use secure communication channels instead.
What you should know
E2EEis short for End-to-End Encrypted, and it means that only the people on the devices who are on the call can listen to what's being said. Anyone who tried to listen to the calls while it travels through the network would only "hear" digital noise.
- Though many apps support "digital voice calls", not all of them support
E2EE, or don't support it by default. So below we'll recommend which apps to use based on whether their voice calls are encrypted end-to-end by default.
- Not supporting
E2EEdoes not mean that the chats are completely insecure or unencrypted. But it does means that another party (typically the platform itself) has access to your messages. So, while you may trust Facebook (i.e. Messenger) with your text messages, there were reports in 2018 where Hackers were said to have obtained private messages of 120 million Facebook accounts. The chances are somewhat slim that your encrypted messages will end up in the wrong hands without E2EE, but it's not impossible. By using E2EE you remove this particular risk. That's why we recommend using it where possible.
What you should do
1. Use Signal for your Voice Calls
2. Other Voice Call apps defaulting to E2EE
Signal is the preferred method for voice calls. However, other apps also offer E2EE voice calls by default. You also do not need to be worried about the operators of the following platforms from listening in on your calls:
- Apple Messages / FaceTime - but it's only available on Apple devices.
- Telegram - calls are E2EE by default, but for text message you need to opt-in to E2EE (by using "Secret Chats").
- Rakuten Viber - but only for calls between two people. For group calls it doesn't use E2EE.
3. Do not use these apps for sensitive voice calls
The following apps either don't support E2EE voice calls, or don't have the option set by default, so should best be avoided when discussing sensitive information over a call:
- Facebook Messenger - Offers "Secret Conversations", but doesn't offer E2EE by default.
- Microsoft Skype - Offers "Private Conversation", but doesn't offer E2EE by default.
- Microsoft Teams - Microsoft announced it would bring E2EE to Teams, but it will likely only be opt-in and for 1-on-1 calls.
- SalesForce Slack - Slack will not supported E2EE.
- Zoom - Currently has "E2EE" in technical preview, but doesn't offer E2EE by default. See 💻-🖥️-📱 Safely host Zoom for the features which are disabled if you opt-in to use E2EE.