IDK, trusting a remote system just seems bad. Either give me the data to process locally, or I'll give you some data you couldn't possibly understand and you do

IDK, trusting a remote system just seems bad. Either give me the data to process locally, or I'll give you some data you couldn't possibly understand and you do some stuff to it and return the results, having never known the meaning of the data. In Signal's case, they could just let you send messages that might never be received because the contact doesn't currently have the app. Also gives the receiver plausible deniability unless they respond. And could help get more people on Signal if they did the "Someone sent you a message, download the app now" trick.