Government implements DNSSEC on the .gov domain

The government has digitally signed the .gov top-level domain, effectively implementing the Domain Name System Security Extensions (DNSSEC) protocols throughout the top tier of the federal Internet space.

“On Feb. 28, 2009, DNSSEC became operational on .gov after the program successfully completed all required DNSSEC testing,” the General Services Administration, lead agency in the program, said today in a statement.

The signing came one month after the January deadline set by the Office of Management and Budget in August. The deadline had been pushed back when GSA officials found during testing that an additional feature was needed in the DNSSEC software being used.

“The .gov DNSSEC public key was registered [Feb. 28] with the Internet Assigned Numbers Authority (IANA) Interim Trust Anchor Repository (iTAR) and became available for use as the published trust anchor for .gov validation,” GSA said in its statement. “The .gov Top Level Domain is now considered an active DNSSEC signed zone.”

The next step in the governmentwide effort to better secure its DNS is for agencies to begin deploying DNSSEC within their second-level domains, such as gsa.gov, by the end of the year.

The 26-year-old Domain Name System maps domain names to IP addresses and underlies nearly all Internet activities. DNS replaced a naming system known as the Host Table, which dates back to the Internet’s predecessor the Arpanet and predates the implementation of TCP/IP. A centrally managed file maintained by the Network Information Center at Stanford University was updated every week or so to map between host names and location on the network.

That was adequate during the pioneering days of the interconnected network, but would not scale to the levels needed as the Internet grew. DNS is a distributed, hierarchical scheme that lets everyone see into it for address look-ups without having to maintain a separate copy.

DNS has been successful at scaling to serve the Internet community, but like the rest of the Internet infrastructure, it was not built with security in mind. The possibility of DNS caches being poisoned by hackers to misdirect or hijack traffic has been known for some time, but last July a significant flaw in the protocols was announced that made securing the system more urgent.

DNSSEC lets DNS queries and responses be digitally signed so they can be authenticated and are harder to spoof or manipulate. But both sides of the exchange must be using DNSSEC in order for it to work. Implementation within the entire .gov space is expected to promote expanded use of the protocols.

In late 2006, new federal information security requirements called for agencies to use DNSSEC signatures on DNS servers that are classified as moderate or high impact information systems. Little implementation was done, however, in part because most servers were classified as low-impact and in part because managing DNS can be complicated, involving the management of cryptographic keys and digital signatures that are valid for only a month.

In the wake of last July’s vulnerability announcement, OMB issued a memo requiring deployment of DNSSEC to the top-level .gov domain by January 2009.

“This policy requires that the top-level .gov domain will be DNSSEC signed and processes to enable secure delegated subdomains will be developed,” the memo states. “Signing the top-level .gov domain is a critical procedure necessary for broad deployment of DNSSEC, increases the utility of DNSSEC and simplifies lower level deployment by agencies.”

That is the step completed Feb. 28. The memo also required agencies to create a plan and milestones for deployment of DNSSEC to their information systems by December 2009. The National Institute of Standards and Technology is updating its guidelines for implementing DNSSEC in its Special Publication 800-81, “Secure Domain Name System Deployment Guide.” The basic steps outlined in the guidance for deployment of the DNSSEC for zone information are:
  • Install a DNSSEC-capable name server implementation;
  • Check zone file(s) for any possible integrity errors;
  • Generate asymmetric key pair for each zone and include them in the zone file;
  • Sign the zone;
  • Load the signed zone onto the server;
  • Configure name server to turn on DNSSEC processing and
  • Optional, send copy of public key to parent for secure delegation.

Because deploying and maintaining DNSSEC within an enterprise can be complex, NIST has established the Secure Naming Infrastructure Pilot (SNIP) to give administrators some real-world experience managing a signed DNS zone on a live network. SNIP is a joint project of NIST, the Homeland Security Department and Sparta Inc. of Arlington, Va., a Defense Department and intelligence contractor that provides, among other things, network operations. SNIP provides a test domain on which participants can mirror their current DNS operations and learn what impacts DNSSEC will have on those operations and on the performance of DNS servers themselves.

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