Comcast's customers won't see any change in their Internet service as a result of the ISP's DNSSEC support. That's because few Internet applications currently support the standard. One exception is the Firefox Web browser, which has a DNSSEC plug-in that shows a user when a Web page they are visiting has been verified or spoofed.
Once a Web site cryptographically signs its domain, Comcast's DNSSEC servers will validate that the Web site's security key is accurate and hasn't been tampered with by a hacker. If the key validation fails, the end user won't be directed to the phony Web site.
DNSSEC "is a fairly technical subject. I don't think it's something that the average customer is aware of," Livingood says. "But some of the large commercial Web sites that are customers are aware of it. We expect very large banks to implement DNSSEC as soon as the associated top-level domain supports it."
In order for DNSSEC to be effective, it must be deployed across the Internet infrastructure from the root server clusters, to the servers that run .com and .net and other top-level domains, and then down to the servers that cache content for individual Web sites. ISPs must support DNSSEC resolution for their customers, and users must have Web browsers and other applications that can validate queries using the standard.
Once it is widely deployed, DNSSEC will prevent cache poisoning attacks, where traffic is redirected from a legitimate Web site to a fake one without the Web site operator or user knowing. Cache poisoning attacks are the result of a serious flaw in the DNS that was disclosed in 2008 by security researcher Dan Kaminsky.
"DNSSEC is a critical thing that needs to be adopted," Livingood says. "It's very exciting that we're the first large ISP in the U.S. that is adopting this for our subscribers."
In a separate announcement last week, Comcast said it has donated $15,000 to a fund run by NLnet Labs that will encourage application developers to support DNSSEC.
Read more about wide area network in Network World's Wide Area Network section.