Investigating Encrypted DNS Blocking in India
In October 2020, we collaborated with Divyank Katira and Gurshabad Grover, researchers at the Centre for Internet & Society, India, to implement and evaluate a new OONI experiment focused on detecting DNS censorship.
This new OONI experiment, called dnscheck, focuses on detecting the blocking of encrypted DNS transports such as DNS over TLS and DNS over HTTPS. Its methodology improves upon the measurement methodology OONI previously used to measure DoT blocking in Iran.
The implementation, written by Divyank Katira, is currently only available to users of the miniooni research client. We are however planning on promoting the dsncheck experiment as a first class experiment that will run by default as part of the “websites” experiments group.
To validate dnscheck, we tested access to popular DoT and DoH resolvers from four popular Indian ISPs covering a large majority of the Indian internet subscriber base. We found that all these resolvers were accessible, perhaps because network neutrality obligations in India do not allow ISPs to arbitrarily block resources.
Read the full research report on the Centre for Internet & Society, India’s website! Stay tuned for future updates that will integrate the dnscheck experiment into OONI probes!