# SSO
- a third party is queried to verify authentication
- apples, google, facebook
- no local password
# MFA
- username+password AND another mechanism (biometric, OTP, HW token, etc.)
# IAM (Identity & Access Mgmt)
- identity: username and other biographic details
- authentication: verify password, NFA, etc.
- authorization: verify access based on need to know, least priv, etc.
- related protocols:
- LDAP (lightweight directory access protocol) stores identity, authentication, and/or authorization info
- AD (active directory) leverages LDAP
- PAM (pluggable authentication modules)
- can interface with LDAP
- SSSD (system security services daemon) RHEL orchestrator for identity and AAA
- interfaces with LDAP, AD, PAM, etc. and caches info