I have found that one of the communication mechanisms used does use HTTPS on subdomains, typically secure.*, as explained at: https://cirosantilli.com/cia-2010-

I have found that one of the communication mechanisms used does use HTTPS on subdomains, typically secure.*, as explained at: https://cirosantilli.com/cia-2010-covert-communication-websites#cgi-comms https://cirosantilli.com/cia-2010-covert-communication-websi... E.g.: https://secure.globalnewsbulletin.com https://secure.globalnewsbulletin.com However my quick and naive searches on https://search.censys.io/ https://search.censys.io/ for other certificates with the same public key failed.