It's almost certainly the carriers imposing this restriction. The reason these features took so long is because, as they did for SMS, every single carrier across the world has to get on board with this. , so I'm sure that's the reason it's not encrypted. The Messages app might be a Google product, but the underlying transport has to be implemented by carriers, and I'm sure there are many, many carriers who aren't interested in encrypting the messages that are carried across their networks (either because they don't have the technical competency, they want the data for themselves, or they have to comply with local law enforcement regulations about texting).
This is not to excuse the lack of encryption, but the finger should probably be pointed more at carriers (and maybe OEMs) than at Google.
One question I have is whether Google-account to Google-account messages will be encrypted, like how Apple does it with their iMessage/SMS boundary within the same app...
Encryption can be done on device. Google as the major player could simply implement it without carriers' approval and without changing underlying protocols. Instead they have chosen to route unencrypted messages through their servers.
> or they have to comply with local law enforcement regulations about texting.
Carriers can record encrypted messages and provide them to police and courts.
Is there any reason someone couldn't make an sms client that gives the option of encryption assuming the person you are conversing with was using a client following the same encryption protocol? It would require a few automated texts to exchange keys but would allow encrypted communication over sms easily.
I'm guessing there just isn't a big enough market for it given that people are willing to create an account with WhatsApp to get the same thing.
That's exactly what TextSecure (now Signal) used to do[0]. Since the code is open-source, somebody has forked the SMS code and apparently kept it alive[1]. (It's even on both F-Droid and Google Play.)
This is not to excuse the lack of encryption, but the finger should probably be pointed more at carriers (and maybe OEMs) than at Google.
One question I have is whether Google-account to Google-account messages will be encrypted, like how Apple does it with their iMessage/SMS boundary within the same app...