A Survey on DNS Security Issues and Mitigation Techniques

The Domain Name System (DNS) is the backbone of the internet. It is a distributed hierarchical database which stores resource records like A, MX, AAAA, CNAME. The whole DNS is classified into three layers - root, top-level domain (TLD) and authoritative DNS servers. Each level has its own responsibility to resolve certain categories of domain names. It is very difficult for us to memorize the IP address of each site which we need to visit. In this case, the DNS comes into rescue to figure out the corresponding IP address a domain points to. In the current world, the internet is an inevitable part of our life and DNS is the soul of the internet. Due to this reason, DNS is a major attack target like amplification attack, cache poisoning attack, DNS hijacking, NXDomain attack and Phantom domain attack. These attacks could create a serious security threat to internet users. Threats can be a simple redirection to potentially stealing user credentials. Even though different mitigation techniques are available, the threat still exists. In this paper, we present our survey of the existing research and its shortcomings on securing the DNS. We have also introduced a novel idea which uses blockchain technology to validate the response sent by the DNS servers.