iMAP Myanmar 2023 Internet Censorship Report | Page 56 Verifying OONI measurements Confirmed blocked OONI measurements were based on fingerprints recorded here https://github.com/ooni/blocking-fingerprints. These fingerprints are based on either DNS or HTTP blocking. The fingerprints recorded as confirmed blockings are either those implemented nationally or by ISPs. Hence, heuristics as below were run on raw measurements for all countries under iMAP to further confirm blockings. Firstly, IP addresses with more than 10 domains were identified. Then each IP address was checked for the following: Does the IP in question point to a government blockpage? Yes No, page timed out or shows Content Delivery Network (CDN) page. Confirmed blocking What information can we get about the IP by doing a whois lookup? Government or Local ISP* CDN / Private IP Confirmed blocking Do we get a valid TLS certificate for one of the domains in question when doing a TLS handshake and specifying the SNI Yes No, there were blocking fingerprints found. No, timed out False positive Confirmed blocking Sampled measurement is analyzed on OONI Explorer. *Note: In the case of India, there was evidence of popular websites hosting their site on the ISPs network for quicker loading times as the ISPs sometimes offer such edge networking services. Hence, websites redirected to local websites are only marked as “Potentially Blocked”.