IP-based networks, including the Internet, route information between computers based on their IP address (such as 208.77.188.166). Directly using these numbers would cause many problems, so Domain Name System (DNS) is a critical service of such networks. DNS accepts a domain name (such as www.example.com) and responds with information about that name, such as its matching IP address. DNS can also perform reverse look-ups (given an IP address, return the corresponding name). Unfortunately, DNS was not designed to be secure. DNSSEC was designed to protect Internet resolvers (clients) from forged DNS data. It is widely believed that deploying DNSSEC is critically important for securing the Internet as a whole, but deployment has been hampered by some difficulties. Some of these problems are in the process of being resolved, and deployments in various domains have begun to take place. Read the full background at DNSSEC Wikipedia