Is there a secure way to share a private Git repository with others by pushing it in an encrypted format to a general-purpose server hosted by a hosting service?

There's a very long thread about this on http://kerneltrap.org here: http://kerneltrap.org/mailarchive/git/2008/3/13/1153274/thread In short: It's really hard to do.  There's a similar question on StackOverflow here: http://stackoverflow.com/questions/2456954/git-encrypt-decrypt-remote-repository-files-while-push-pull That makes it seem like you could put in a PGP layer as a smugde filter.  I'm not familiar with this technique, so use at your own risk. :)

I'd not risk this. Now there're plenty of private hosting services that are offering a decent free plan. Check out this answer on stackoverflow: http://stackoverflow.com/questions/2058076/free-hosting-service-for-private-and-public-git-repositories/5051295

You might want to check out git-crypt, I have not used it, but it seems reasonable: http://www.agwa.name/projects/git-crypt/