The question is who would do the signing and revocations. Whoever does that would indeed have a great amount of control over the internet. A single government agency should not have that sort of power to make a (for lack of better term), "no surf list" of IP space...
You might try taking a look at the various presentations at NANOG/RIPE/ARIN/ APNIC/APRICOT about the whole idea. Central point: the entity that gives you a suballocation of its own address space signs something that says you now hold it. No governments involved. Here are a few URLs to start you off: NANOG 36 Feb 2006: What I Want for Eid ul-Fitr, An Operational ISP & RIR PKI http://www.nanog.org/mtg-0602/pdf/bush.pdf NANOG 38 Oct 2006: Serious Progress on X.509 Certification of RIR Resource Allocations http://www.nanog.org/mtg-0610/presenter-pdfs/bush.pdf ARIN XVII April 2006: X.509 Resource and Routing Certificate Panel http://www.arin.net/meetings/minutes/ARIN_XVII/PDF/monday/x509-huston.pdf http://www.arin.net/meetings/minutes/ARIN_XVII/PDF/monday/x509-kent.pdf RIPE 52 Apr 2006: A PKI for IP Address Space and AS Numbers http://www.ripe.net/ripe/meetings/ripe-52/presentations/ripe52-plenary-pki.p... RIPE 53 Oct 2006: Using Resource Certificates - A Progress Report on the Trial of Resource Certification http://www.ripe.net/ripe/meetings/ripe-53/presentations/using_res_certs.pdf RIPE 51 Oct 2005: APNIC Trial of Certification of IP Addresses and ASes http://www.ripe.net/ripe/meetings/ripe-51/presentations/pdf/ripe51-address-c... APNIC Mar 2006 APNIC resource certification update http://www.apnic.net/meetings/21/docs/sigs/routing/sig-routing-pres-ggm-reso... APRICOT Mar 2006: A PKI to Support Improved Internet Routing Security http://www.apricot2006.net/slides/conf/wednesday/Address%20Space%20PKI%20(AP... Work ongoing in the IETF SIDR working group: http://www.ietf.org/html.charters/sidr-charter.html --Sandy Murphy