DNSSEC Implementation Held Up By Tech Delays

Jack Spine writes "VeriSign has said that the main obstacle to DNSSEC implementation has been technical delays. The large size of the .com and .net domains would have made it impractical to deploy earlier versions of DNSSEC, according to VeriSign vice president of naming services Pat Kane. Deployment of DNSSEC will close a major security flaw in the DNS, the internet's equivalent to a telephone directory. The problem of DNS cache poisoning was thrown into sharp relief by researcher Dan Kaminsky last year."

Comments

Why use digital signatures?

[Myria]

This really seems like a ploy by VeriSign and friends to make ever more people and companies to purchase signed certificates at $100/year or whatever. I don't feel that it's necessary to use digital signatures to secure the system.

The fundamental flaw of DNS is that the "nonce" - the one-time-use random constant used to prevent spoofing - is only 16 bits. If you're going to change the DNS protocol, why not just increase the size of that field to 64 bits and be done with it? Then it's only a software change to DNS servers rather than an expensive certificate and far less of an administrative headache.

Also, I don't think that it's even necessary to change the protocol. The protocol allows for multiple DNS queries in one packet. When doing a DNS query, ask for both www.google.com and a nonce domain like eujrdyhtaeoym.example.com. If the query comes back saying that eujrdyhtaeoym.example.com does not exist (or even if it says it does!), you know nobody is spoofing DNS queries back at you because unless they were snooping traffic, they wouldn't have a way to know that your nonce was eujrdyhtaeoym.

Re:Why use digital signatures?

[Burdell]

You should understand DNSSEC before criticizing it. It doesn't work with SSL-style certificates that have to be signed by a recognized certificate authority. Also, it doesn't change the existing protocol, it extends it in a (mostly) backwards-compatible way. DNS servers just have to know how to request and handle the new additional records; old servers and clients keep working fine.

Your proposed solutions only fix one small piece of the DNS problem, that of spoofed network packets. DNSSEC authenticates the entire response chain, so that (for example) you can be sure that your ISP isn't modifying responses to point you somewhere else (such as their servers) rather than what you requested.

With DNSSEC, you could possibly eliminate the SSL certificate authorities and use signed DNS records to include the certificate information (so you can make sure that when you go to https://www.foo.com/, you really got www.foo.com's certificate and not that of a man-in-the-middle attacker).