Some do, but most likely not under ftp.*.debian.org name. AFIAK there's no official list of HTTPS-enabled mirrors. An incomplete, possibly out-of-date list is h

Some do, but most likely not under ftp.*.debian.org name. AFIAK there's no official list of HTTPS-enabled mirrors. An incomplete, possibly out-of-date list is here: https://lists.debian.org/53B6150A.3000602@at.or.at https://lists.debian.org/53B6150A.3000602@at.or.at Besides that, https://deb.debian.org/ https://deb.debian.org/ provides HTTPS mirror backed by CDNs.