What problem does DNSSEC solve?
DNSSEC helps to prevent DNS cache poisoning. Cache poisoning is a corruption of the DNS that enables the spread of viruses, worms, and other malicious files/content. Cache poisoning occurs when data is provided to a caching name server that did not originate from an authoritative Domain Name System (DNS) source. Once a DNS server receives non-authentic data and caches it for future use, it will then supply that non-authentic data to its client servers. The impact of cache poisoning on end users is that they may be directed to IP addresses they did not intend to reach, and may not be aware of the associated risks.