DNS is one of the fundamental building blocks of the Internet. It's used any time you visit a website, send an email, have an IM conversation or do anything else online. While OpenDNS has provided world-class security using DNS for years, the underlying DNS protocol has not been secure enough for our comfort.
The "last mile" is the portion of your Internet connection between your computer and your ISP.
DNSCrypt is a way of securing the "last mile" of DNS traffic and resolving an entire class of serious security concerns with the DNS protocol.
There have been numerous examples of tampering, or man-in-the-middle attacks, and snooping of DNS traffic at the last mile and it represents a serious security risk that we've always wanted to fix.
In the same way the SSL turns HTTP web traffic into HTTPS encrypted Web traffic, DNSCrypt turns regular DNS traffic into authenticated and encrypted DNS traffic that is secure from eavesdropping and man-in-the-middle attacks.
It doesn't require any changes to domain names or how they work, it simply provides a method for securely encrypting communication between our customers and our DNS servers in our data centers.