Completely agreed. Synchronized passwords are risky compared to LDAP. LDAP is definitely proven (esp in a LAN/non-cloud environment), but isn't perfect: if LDA

Completely agreed. Synchronized passwords are risky compared to LDAP. LDAP is definitely proven (esp in a LAN/non-cloud environment), but isn't perfect: if LDAP is DoS'ed (even from the very servers that it's authenticating for), then you can't log into any servers (or if a maintenance window exceeds the cache window, or even if it's just taken offline via hostname change or something). It also doesn't help much with user-based UX (i.e., key rotation, granting someone additional rights usually has to go through a centralized IT dept, etc) and caching is pretty awful, and it's a pain to securely configure. Lots of risk of inadvertently opening a hole through an insecure PAM/NSS configuration or ACL's. The worst part with LDAP is the long and sordid history of LDAP and KRB5 root-level vulnerabilities. Even with all of these drawbacks, LDAP probably less risky than storing (even different) hashes of the same password across thousands of boxen! Disclaimer: I'm the CTO @ https://Userify.com https://Userify.com ; we build an SSH Key management tool that's specifically designed for cloud servers.