/ˈɛlˌdiːˈæps/
n. “LDAP, but encrypted for grown-ups.”
LDAPS, or Lightweight Directory Access Protocol over TLS/SSL, is the secure version of LDAP. Where plain LDAP transmits queries and responses in cleartext, LDAPS wraps this communication in Transport Layer Security (TLS) or Secure Sockets Layer (SSL), protecting sensitive information like usernames, passwords, and directory attributes from eavesdropping and tampering.
Organizations often use LDAPS when connecting to directory services such as Active Directory or OpenLDAP from remote applications, email systems, or single sign-on solutions. By encrypting the channel, administrators can safely transmit authentication requests, fetch user information, or update entries without exposing confidential data on the network.
Conceptually, LDAPS behaves identically to standard LDAP: the same queries, the same hierarchical tree structure, the same attributes. The difference lies entirely in the transport layer, which enforces confidentiality, integrity, and sometimes server authentication using certificates. Applications configured for LDAPS typically connect over port 636 rather than the default 389 used by unencrypted LDAP.
A practical example: a corporate VPN client may authenticate a user by querying an LDAPS endpoint on the central directory server. Even if the network between client and server is insecure, the credentials are encrypted, preventing interception. Likewise, an internal HR system can safely synchronize employee records over LDAPS without exposing personally identifiable information.
Security best practices for LDAPS include using trusted TLS certificates, validating server identity, and disabling obsolete encryption algorithms. Misconfigurations, such as using self-signed certificates without validation, can negate the security benefits, so administrators must enforce strict certificate management policies.
In short, LDAPS is the evolution of LDAP for the modern, security-conscious network. It preserves all the functionality of LDAP while ensuring that the sensitive conversations between clients and directory servers remain private and tamper-proof. This makes it a cornerstone of secure identity management in enterprise environments.