Two Sides of the Shield: Understanding Protective DNS Adoption Factors

Protective DNS (PDNS) filters out DNS requests leading to harmful resources. PDNS is currently being promoted by various governments and industry players - some global public DNS providers offer it, as do some government-sponsored DNS resolvers. Yet, are end users even interested in adopting it? The extent of current PDNS usage, as well as the factors that encourage or discourage end-users' adoption, have not been studied. We found that overall PDNS adoption is minimal, though in some countries over 20% of the DNS queries are being answered by these types of resolvers. Four human-subjects studies were undertaken to understand end-user adoption factors: a survey with 295 consumers; 24 interviews with ISP customers offered a free PDNS after a malware infection; 12 interviews with public and private enterprise professionals, and 9 interviews with DNS technology specialists. We found that users are more likely to use PDNS if operated by their own ISP rather than the government. For enterprises, we uncovered that access to global threat intelligence, a layered security strategy, and compliance with regulations were the main factors for PDNS adoption. The DNS technical specialists highlighted broader challenges of PDNS adoption such as transparency and centralization.