I am probably telling you what you already know, but for the ones who don't know it yet:
Secure BGP (S-BGP): http://www.ir.bbn.com/projects/s-bgp/ http://www.nanog.org/mtg-0306/pdf/bellovinsbgp.pdf http://www.nwfusion.com/details/6484.html?def
and of course the sister by amongst others Cisco:
Secure Origin BGP (SO-BGP): http://bgp.potaroo.net/ietf/idref/ draft-ng-sobgp-bgp-extensions/ http://www.nwfusion.com/details/6485.html http://www.nanog.org/mtg-0306/pdf/alvaro.pdf
etc... most people know how to google I guess ;)
Aka BGP with certificates and other nice tricks.
And, of course, the RPSEC working group draft that is supposed to target the BGP requirements for those proposed systems is... http://www.ietf.org/internet-drafts/draft-ietf-rpsec-bgpsecrec-01.txt The folks who worked on S-BGP and SO-BGP participated in it's creation (as well as several operators). Please note that there are more than just two proposed mechanisms for securing BGP. The two mentioned above are just the most popular <grin>.