----- Forwarded message from Jim Small <jim.sm...@cdw.com> ----- Date: Tue, 11 Jun 2013 01:02:54 +0000 From: Jim Small <jim.sm...@cdw.com> To: IPv6 Hackers Mailing List <ipv6hack...@lists.si6networks.com> Subject: Re: [ipv6hackers] opportunistic encryption in IPv6 Reply-To: IPv6 Hackers Mailing List <ipv6hack...@lists.si6networks.com>
Hi Owen, > > The fundamental challenge for encryption is key distribution and > management: > > * How do I authenticate the intended recipient(s)? > > This is a traditional challenge with many traditional solutions, all of which > have > tradeoffs, especially in M2M communications. > > > * How do I distribute a key without letting anyone except the intended > recipient(s) get it? > > DH pretty well solves this, no? Yes and no. DH is a good answer, but IKE/IPsec still requires pre-shared keys or RSA key pairs to start with. So I think there would be some value in a keying system that allows some kind of controlled federation without having to depend on pre-shared keys, PKI, or DNSSec. > > * How do I manage the key to periodically change it while keeping it > confidential? > > Again, DH with PFS makes this a solved problem AFAIK. True - but only after the initial hurdle of having a pre-shared key or RSA key pair. > > * How do I notify the recipient if the key was compromised or is otherwise > invalid? > > This doesn't seem all that hard so long as a rekey instruction is built into > the > protocol. I believe that's already the case with IPSEC SAs, no? Well - if we take DH, it's true once we've established a connection. What about if we haven't? Really the question I'm asking - if we have two independent parties, how do they validate each other without a trusted 3rd party? Current options: * pre-shared keys (but not scalable and keys tend to be weak to make it easy to share - keys are rarely if ever rotated) * PKI - good but complex and as Moxie Marlinspike has demonstrated with others many flaws, abused by governments * DNSSec - interesting one to watch but not really ready for wide spread use yet, needs greater adoption * Manual/3rd party CA - possible if one party trusts the other or in a service provider scenario Did I miss any viable wide spread options? I know there are lots of theoretical ones but I'm talking about significantly deployed ones - say used by at least 1 million parties. > Vs. this paper, I think that opportunistic IPSEC, ala Micr0$0ft's "direct- > connect" or whatever they call it product is quite a bit more viable. > It depends on AD as a PKI distribution mechanism for authentication. DirectAccess is neat - but it's not exactly a break through. DA is just a service based (aka UNIX/Linux daemon) IPv6 IPsec VPN with good provisioning and automatic IPv4 tunneling. It's essentially a nice packaging of certificate-based IPsec leveraging Windows Active Directory provisioning. There are some good ideas in this paper. I just think there are some things missing - at least from my cursory reading of it. --Jim _______________________________________________ Ipv6hackers mailing list ipv6hack...@lists.si6networks.com http://lists.si6networks.com/listinfo/ipv6hackers ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org";>leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://ativel.com http://postbiota.org AC894EC5: 38A5 5F46 A4FF 59B8 336B 47EE F46E 3489 AC89 4EC5 -- Too many emails? Unsubscribe, change to digest, or change password by emailing moderator at compa...@stanford.edu or changing your settings at https://mailman.stanford.edu/mailman/listinfo/liberationtech
