I recently stumbled upon sig2dot, a gpg/pgp keyring graph generator. In fact this seems to have been around for some time, but I’d never come across it before. It can be used to generate a graph of all of the signature relationships in a GPG/PGP keyring, and, like other visualisation tools, this graphical image producing program can give new insight into relationships between objects.
The sig2dot program itself is available in the debian/ubuntu repositories in the package called “signing-party”. But unless you want to install a shed load of other unnecessary cruft along with it (exim? for god’s sake, why?), I recommend you simply pull the perl code direct from the author’s site. Along with the sig2dot program itself, you will need “neato” from the graphviz package and “convert” from the wondrous imagemagick package suite. If you don’t already have those installed then it is pretty safe to pull them from your distro’s package repository.
That done, try the following:
first create an ascii graphviz dot file ready for neato
$ gpg –list-sigs –keyring ~/.gnupg/pubring.gpg | sig2dot.pl > ~/.gnupg/pubring.dot
(that is “minus minus list-sigs” and “minus minus keyring”) now convert to a postscipt file
$ neato -Tps ~/.gnupg/pubring.dot > ~/.gnupg/pubring.ps
before using imagmagick to convert to a png graphic
$ convert ~/.gnupg/pubring.ps ~/.gnupg/pubring.png
Those of you with gpg keyrings may wish to try it out (and no. I’m not going to show you mine).