It’s a valiant effort, to be sure. Notifications may be less reliable, but that’s understandable. A few notes, however.
This guy is clearly very, very smart. However, security researcher may be a little generous. The linked blog post says he’s a high school student. That’s incredible, fantastic work. Still not sure I want to trust the reverse engineering of one person of necessarily limited experience.
This is the other weak spot. Even if the reverse engineering is perfect and Apple can’t change it out from under them, the implementation is a different question. That also needs to be basically perfect and something Apple can’t quietly break with plausible deniability.
This is perhaps the biggest difference. As I understand it, on iPhone iMessage keys are stored in Secure Enclave and are supposed to be essentially impossible to get at. Not sure if it’s the same here.
Overall an extremely impressive effort. It raises a few interesting arguments both for and against Apple just doing this themselves. And I have to wonder if iMessage is important enough why not use use a cheap ipad or old iPhone. And with RCS “coming soon” the advantages of this should quickly evaporate.
Like I said in another post, this guy has an unfortunate history of great ideas which are quickly destroyed by Apple.