Google has begun broadly enabling case randomization in domain queries sent to authoritative name servers, in an effort to make cache poisoning attacks less effective.
This means queries for a domain like example.com, if handled by Google Public DNS, could be reformatted eXaMpLe.coM when the request is transmitted to DNS servers to look up. While this may get noticed by admins scrutinizing network traffic, the spicy formatting is not visible to the general public so no one should be any the wiser – if everything goes well.
When people try to visit a website – such as theregister.com – whatever browser or app they’re using queries the site’s domain name using the Domain Name System (DNS) to discover the IP addresses for the servers hosting the site. Such a DNS query commonly passes through a recursive DNS service that contacts other name servers until it ultimately gets an answer from an authoritative name server.