South Korea obligates ISPs to use SNI filtering

The Korea Communications Standards Commission (KCSC) has obligated all Internet service providers (ISPs) in Korea to filter all server name indication (SNI) requests, a process that provides access to an unencrypted list of all websites visited from within South Korea. Previously KCSC used the domain name system (DNS) filtering process to search the domains users were trying to visit, compare them to blacklisted sites, and redirect them to the warning site if needed. However, as this process of filtering did not work for HTTPS websites, KCSC introduced the SNI filtering process.