Ok. so, encrypted data is sent from the computer to the server and spread to other computers. And, let say there is a person in the middle attack?
Here is where I'm confuse; The client/server need to decrypt the data with the key, but if the key can be seen by the client computer then the attacker can see it in the data as well. The key can be encrypted, but another key would have to be sent un-encrypted. so how do you pass the "key" to decrypt the data?
So when I hear new chat system saying they are enprypted their client messages; I'm wondering, how are they doing it? When hacker can try to find the key in thier data and decrypt the message.