shattered is not (yet) a practical attack on git because of the way the data is represented before being hashed. Managing to get a SHA1 collision while simultan

shattered is not (yet) a practical attack on git because of the way the data is represented before being hashed. Managing to get a SHA1 collision while simultaneously getting a valid git object and a meaningful commit (with, say, a backdoor inserted instead of pseudorandom garbage that will fail to compile) is still vastly too difficult to be practical, at least with publicly available knowledge. Regarding the overhead I don't know what you mean and you're really grasping at straws at this point, how is validating a GPG signature harder than validating that, say, a website is actually hosting the official repo of a project instead of a malicious fork? What if my self-hosted website gets hacked mitm'd or DNS highjacked? GPG can still be used to validate that my commits are valid in these situations. Actually I'm not even tied to github or anything else in this situation, any mirror can be used without fear as long as my keys are secured.