Securing the Internet’s DNS

April 24, 2008 – 3:04 PM

The Internet is slowly inching closer to ratcheting up the security of its Domain Name System (DNS) server architecture: The Internet Corporation for Assigned Names and Numbers (ICANN) plans to go operational with the secure DNS technology, DNSSEC, later this year in one of its domains.

ICANN officials said the organization plans to add DNSSEC to its .arpa Internet domain servers, and that the .org domain servers (run by PIR) as well as the .uk servers also will go DNSSEC soon. Country domains .swe (Sweden), .br (Brazil), and .bg (Bulgaria ) already run the secure version of DNS for their domain servers.

DNSSEC, which stands for DNS Security Extensions, digitally signs DNS records so that DNS responses are validated as legitimate and not hacked or tampered with. That ensures users don’t get sent to phishing sites, for example, when requesting a legitimate Website. DNS security increasingly has become a concern, with DNS prone to these so-called cache poisoning attacks, as well as distributed denial-of-service (DDOS) attacks like the one last year that temporarily crippled two of the Internet’s 13 DNS root servers.

But DNSSEC adoption has been slow in coming, mainly due the complexity of managing the keys. Converting .arpa — a domain mostly relegated to Internet research sites — to DNSSEC isn’t quite the same as securing .com, but it could signal that DNSSEC is finally ready for prime time, experts say.

ICANN says its latest DNSSEC move doesn’t signal an all-out move to DNSSEC, however. “Every time another top-level domain signs on, that’s progress,” says Richard Lamb, an engineer with ICANN who helped build its DNSSEC testbed. “Whether it means the DNS root servers [will go DNSSEC] in the near future, I don’t know.”

David Piscitello, a member of ICANN’s Security and Stability Advisory Committee, says he considers the latest wave of DNSSEC adoption plans a “glass half-full.”

“Some might point to the fact that we are still ‘ticking off zones’ as they implement DNSSEC indicates there’s little support. DNSSEC isn’t the kind of extension you willy-nilly toss into a critical infrastructure without considerable effort, and much of that effort is not visible or newsworthy,” Piscitello says. “Arpa and Org may be strong indicators that the community is building confidence in DNSSEC protocols; name server implementations with DNSSEC are proving themselves in production environments; and people are spending time deploying DNSSEC for the security measures it provides instead of complaining about the threats it does not mitigate.”

DNSSEC digitally signs DNS records but doesn’t encrypt DNS traffic. And it’s not all there is to securing DNS. Piscitello points out that securing the Net’s DNS infrastructure also requires building it out to better repel DDOS attacks. That means “increasing the capacity, resiliency, and diversity of location of the root name servers to make the DNS more resistant to denial-of-service attacks,” he says.

Other measures include getting rid of “open resolvers,” which often get abused by phishers and other e-criminals, he says, and hardening DNS server and resolver software, as well as adding more real-time monitoring to these servers to detect attack attempts sooner.

Meanwhile, ICANN is working on its DNSSEC testbed to prepare for future DNSSEC adoption. “We are coming up with a system we can deploy. This testbed puts us in a position to be ready if we’re asked by all the right people to assign [DNSSEC] to the root zone as well,” ICANN’s Lamb says. “We’re looking at this testbed to eventually sign arpa” and other domains.

ICANN recently selected and purchased AEP Networks Inc.’s Keyper hardware security modules for generating and storing the keys for the DNSSEC testbed. “The private key is never visible” because it’s all done in the box, Lamb says. And ICANN has been writing DNSSEC code for the DNS servers that it’s put in the public domain.

Source: Dark Reading