The Sentry providing mobile device authentication intermediary services using PKI-based mobile device authentication must only accept end entity certificates issued by DoD PKI or DoD-approved PKI Certification Authorities (CAs) for the establishment of protected sessions.

Non-DoD-approved PKIs have not been evaluated to ensure they have security controls and identity vetting procedures in place that are sufficient for DoD systems to rely on the identity asserted in the certificate. PKIs lacking sufficient security controls and identity vetting procedures risk being compromised and issuing certificates that enable adversaries to impersonate legitimate users.

The authoritative list of DoD-approved PKIs is published at https://cyber.mil/pki-pke/interoperability. DoD-approved PKI CAs may include Category I, II, and III certificates. Category I DoD-approved External PKIs are PIV issuers. Category II DoD-approved External PKIs are Non-Federal Agency PKIs cross-certified with the Federal Bridge Certification Authority (FBCA). Category III DoD-approved External PKIs are Foreign, Allied, or Coalition Partner PKIs.

Deploying the ALG with TLS enabled will require the installation of DoD and/or DoD-approved CA certificates in the trusted root certificate store of each proxy to be used for TLS traffic.

This requirement focuses on communications protection for the application session rather than for the network packet.