Survey And Evaluation of Secure-DNS Alternatives Through Passive Measurements

As security was not among the original DNS design goals, over ten secure-DNS schemes have been proposed to improve security and privacy during the name resolution process. One of the schemes is DNS-over-TLS (DoT), which relies on the Internet's PKI for establishing trust in recursive resolvers. DoT's certificates, have not been investigated comprehensively. This thesis analyzes the certificate ecosystem of DoT in comparison to HTTPS. The results are so far promising. The thesis then surveys secure-DNS schemes, and presents an evaluation framework to assess their security, availability, privacy, and anonymity benefits. Our evaluation illustrates that none of the DNS schemes secures the complete path of the domain name resolution. The results shed light on the challenges of designing a comprehensive and widely-deployable secure-DNS scheme to secure the complete name resolution path. However, as some schemes can be combined, their resultant benefits can address individual shortcomings.