AS11791 SLC-IDENT-AS

SLC-IDENT-AS is IdenTrust, the public-key certificate authority, registered to 5225 Wiley Post Way in Salt Lake City, Utah — the SLC in the handle is the city, not an acronym. IdenTrust has been part of HID Global since 2014 and issues digital certificates to banks, healthcare providers, government agencies and enterprises.

What it's used for

This is a small, first-party operational network for a certificate authority. RIS observes 2 IPv4 prefixes totalling 1,536 addresses and no IPv6, announced through 3 observed neighbours — a /22 and a /23, both registered in ARIN to IdenTrust under a single network handle, and every sampled address in both blocks answers with identrust.com reverse DNS. Registrant, announcer and rDNS all agree, which settles the question this AS range usually raises.

What that space carries is the machinery a CA has to keep online continuously: certificate issuance and enrolment, and above all the revocation infrastructure — OCSP responders and CRL distribution points that relying parties query on every certificate check. Three upstreams for 1,536 addresses is an availability decision, not a traffic one; a CA that goes dark takes validation with it.

Notable

IdenTrust's most consequential act was a favour to someone else: in 2015 it cross-signed Let's Encrypt's intermediate, which is what let the then-new CA be trusted by browsers immediately rather than waiting years for its own root to propagate. A large share of the web's TLS chained back through an IdenTrust root as a result.