How a message travels
Auto transport
Manual carry
You
Plaintext
Telegram
Auto
Matrix
Auto
Signal
Carry
WhatsApp
Carry
SMS
Carry
Email
Carry
One of any number of apps — the channel only ever sees ciphertext
Them
Plaintext
You
Plaintext
Telegram
Auto
Matrix
Auto
Signal
Carry
WhatsApp
Carry
SMS
Carry
Email
Carry
Channel sees only ciphertext
Them
Plaintext