pgp.mit.edu has a web interface which allows you to search based on email addresses. But more easily - since we can trust older commits - doing a git tag -v v3.

pgp.mit.edu has a web interface which allows you to search based on email addresses. But more easily - since we can trust older commits - doing a git tag -v v3.0 will show you the key fingerprint which matches 76E21CBB.