Color me surprised
That noone has mentioned vimb . Like xombrero it is a keyboard driven browser, it uses the webkitgtk as xombrero. Furthermore, it is actively maintained, works in Linux and all the BSDs and the author is already transitioning to webkitgtk4, which with the next release of webkitgtk (v 2.12) will be almost on par with the olgtkd single-process webkit as far as the development blogs suggest [2,3].
In fact, vimb's author is so enthralled with vim, the editor(TM), that vimb's configuration language is viml (yuck!). The browser has no built-in ad blocking, but that's what polipo, Dan's guardian, e2guardian (my recommendation), and other filtering proxies are for.
I use it in Arch Linux so, I prefer to use git snapshots (which is trivial with the AUR). No cryptographic checksums nor PGP signatures, but you get your sourcecode from the developer's mouth and git repository files *have* crypto hashes.