3 ms·

WhatsApp and Signal require the user to verify some identity numbers to prevent MITM attacks. No one does that. If you are OK with that level of protection then

• johannes1234321 7y ago
  It works a little better - it tells me when "the security code" changes. Thus an unnoticed mitm attack has to begin at the beginning of the conversation or at a plausible change of the device. The attacker must be ready to intercept the "you got a new phone? Which one did you get? How broke the previous one?" and keep the conversation plausible. There are certainly targets where such attacks are relevant, but for many it's quite good.