TLS is a form of transport encryption, which encrypts data between the client and the server. End-to-end encryption encrypts data between two clients, so that t

TLS is a form of transport encryption, which encrypts data between the client and the server. End-to-end encryption encrypts data between two clients, so that the server cannot read any messages. The paper claims that while iMessage is marketed as end-to-end encrypted, because of vulnerabilities it is more like it just uses transport encryption.