Git is cryptographically secure, but it’s not foolproof. If you’re taking work from others on the internet and want to verify that commits are actually from a trusted source, Git has a few ways to sign and verify work using GPG.
Introduction to GPG First of all, if you want to sign anything you need to get GPG configured and your personal key installed.
hzxie@XieHaozhe-PC:~$ gpg --list-keys /home/hzxie/.gnupg/pubring.gpg ------------------------------ pub 1024D/381BA480 2007-02-15 uid Johannes Ranke (CRAN Debian archive) <jranke@uni-bremen.de> pub 4096R/3DBF9592 2016-03-28 uid Haozhe Xie (GPG key for GitHub) <cshzxie@gmail.com> sub 4096R/BFEB9969 2016-03-28 If you don’t have a key installed, you can generate one with gpg --gen-key.