in end to end encryption both sides exchange public keys to encrypt message for the other. Their private keys are used to decrypt them...
If you don't have 100% control of the infrastructure you don't know if the app is ONLY SENDING THE PUBLIC KEY, its trivial to send BOTH public and private and strip off the private key on the server... then they can read everything.
The only real encryption is not to say it over or around electronics.
in end to end encryption both sides exchange public keys to encrypt message for the other. Their private keys are used to decrypt them...
If you don't have 100% control of the infrastructure you don't know if the app is ONLY SENDING THE PUBLIC KEY, its trivial to send BOTH public and private and strip off the private key on the server... then they can read everything.
The only real encryption is not to say it over or around electronics.