It’s 2015, and the end of the road for encrypted SMS/MMS in TextSecure.
The TextSecure story started back in 2009, at the dawn of the smartphone era. Back then, TextSecure focused on
securing the transport that everyone coming from feature phones was familiar with: SMS. Today, many things have
changed, and TextSecure now emphasizes the “TextSecure transport,” which uses data rather than SMS. While we remain
committed to supporting plaintext SMS/MMS in addition to the encrypted TextSecure transport so that the app can
function as a unified messenger, we are beginning the process of phasing out support for SMS/MMS as an encrypted
transport in favor of the TextSecure data protocol.