There is still work to be done, but NYU was one of the organizations working on developing and running a rebuilder. The idea is that you pull buildinfo files from https://buildinfo.debian.net/, then try to verify them and if you got the same artifact you sign that you successfully verified this binary package.
A user could then configure "I trust rebuilder X, Y, Z and I require that at least N have successfully verified the package" before installing it.